The recent kernel change in 73f9b911fa ("kprobes: Use rethook for kretprobe
if possible"), introduced a potential NULL pointer dereference bug in the
KRETPROBE mechanism. The official Kprobes documentation defines that "Any or
all handlers can be NULL". Unfortunately, there is a missing return handler
verification to fulfill these requirements and can result in a NULL pointer
dereference bug.
This patch adds such verification in kretprobe_rethook_handler() function.
Fixes: 73f9b911fa ("kprobes: Use rethook for kretprobe if possible")
Signed-off-by: Adam Zabrocki <pi3@pi3.com.pl>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.ibm.com>
Cc: Anil S. Keshavamurthy <anil.s.keshavamurthy@intel.com>
Link: https://lore.kernel.org/bpf/20220422164027.GA7862@pi3.com.pl
Only re-check for direct I/O writes past the end of the file after
re-acquiring the inode glock.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
We received a report[1] of kernel crashes when Cilium is used in XDP
mode with virtio_net after updating to newer kernels. After
investigating the reason it turned out that when using mergeable bufs
with an XDP program which adjusts xdp.data or xdp.data_meta page_to_buf()
calculates the build_skb address wrong because the offset can become less
than the headroom so it gets the address of the previous page (-X bytes
depending on how lower offset is):
page_to_skb: page addr ffff9eb2923e2000 buf ffff9eb2923e1ffc offset 252 headroom 256
This is a pr_err() I added in the beginning of page_to_skb which clearly
shows offset that is less than headroom by adding 4 bytes of metadata
via an xdp prog. The calculations done are:
receive_mergeable():
headroom = VIRTIO_XDP_HEADROOM; // VIRTIO_XDP_HEADROOM == 256 bytes
offset = xdp.data - page_address(xdp_page) -
vi->hdr_len - metasize;
page_to_skb():
p = page_address(page) + offset;
...
buf = p - headroom;
Now buf goes -4 bytes from the page's starting address as can be seen
above which is set as skb->head and skb->data by build_skb later. Depending
on what's done with the skb (when it's freed most often) we get all kinds
of corruptions and BUG_ON() triggers in mm[2]. We have to recalculate
the new headroom after the xdp program has run, similar to how offset
and len are recalculated. Headroom is directly related to
data_hard_start, data and data_meta, so we use them to get the new size.
The result is correct (similar pr_err() in page_to_skb, one case of
xdp_page and one case of virtnet buf):
a) Case with 4 bytes of metadata
[ 115.949641] page_to_skb: page addr ffff8b4dcfad2000 offset 252 headroom 252
[ 121.084105] page_to_skb: page addr ffff8b4dcf018000 offset 20732 headroom 252
b) Case of pushing data +32 bytes
[ 153.181401] page_to_skb: page addr ffff8b4dd0c4d000 offset 288 headroom 288
[ 158.480421] page_to_skb: page addr ffff8b4dd00b0000 offset 24864 headroom 288
c) Case of pushing data -33 bytes
[ 835.906830] page_to_skb: page addr ffff8b4dd3270000 offset 223 headroom 223
[ 840.839910] page_to_skb: page addr ffff8b4dcdd68000 offset 12511 headroom 223
Offset and headroom are equal because offset points to the start of
reserved bytes for the virtio_net header which are at buf start +
headroom, while data points at buf start + vnet hdr size + headroom so
when data or data_meta are adjusted by the xdp prog both the headroom size
and the offset change equally. We can use data_hard_start to compute the
new headroom after the xdp prog (linearized / page start case, the
virtnet buf case is similar just with bigger base offset):
xdp.data_hard_start = page_address + vnet_hdr
xdp.data = page_address + vnet_hdr + headroom
new headroom after xdp prog = xdp.data - xdp.data_hard_start - metasize
An example reproducer xdp prog[3] is below.
[1] https://github.com/cilium/cilium/issues/19453
[2] Two of the many traces:
[ 40.437400] BUG: Bad page state in process swapper/0 pfn:14940
[ 40.916726] BUG: Bad page state in process systemd-resolve pfn:053b7
[ 41.300891] kernel BUG at include/linux/mm.h:720!
[ 41.301801] invalid opcode: 0000 [#1] PREEMPT SMP NOPTI
[ 41.302784] CPU: 1 PID: 1181 Comm: kubelet Kdump: loaded Tainted: G B W 5.18.0-rc1+ #37
[ 41.304458] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
[ 41.306018] RIP: 0010:page_frag_free+0x79/0xe0
[ 41.306836] Code: 00 00 75 ea 48 8b 07 a9 00 00 01 00 74 e0 48 8b 47 48 48 8d 50 ff a8 01 48 0f 45 fa eb d0 48 c7 c6 18 b8 30 a6 e8 d7 f8 fc ff <0f> 0b 48 8d 78 ff eb bc 48 8b 07 a9 00 00 01 00 74 3a 66 90 0f b6
[ 41.310235] RSP: 0018:ffffac05c2a6bc78 EFLAGS: 00010292
[ 41.311201] RAX: 000000000000003e RBX: 0000000000000000 RCX: 0000000000000000
[ 41.312502] RDX: 0000000000000001 RSI: ffffffffa6423004 RDI: 00000000ffffffff
[ 41.313794] RBP: ffff993c98823600 R08: 0000000000000000 R09: 00000000ffffdfff
[ 41.315089] R10: ffffac05c2a6ba68 R11: ffffffffa698ca28 R12: ffff993c98823600
[ 41.316398] R13: ffff993c86311ebc R14: 0000000000000000 R15: 000000000000005c
[ 41.317700] FS: 00007fe13fc56740(0000) GS:ffff993cdd900000(0000) knlGS:0000000000000000
[ 41.319150] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 41.320152] CR2: 000000c00008a000 CR3: 0000000014908000 CR4: 0000000000350ee0
[ 41.321387] Call Trace:
[ 41.321819] <TASK>
[ 41.322193] skb_release_data+0x13f/0x1c0
[ 41.322902] __kfree_skb+0x20/0x30
[ 41.343870] tcp_recvmsg_locked+0x671/0x880
[ 41.363764] tcp_recvmsg+0x5e/0x1c0
[ 41.384102] inet_recvmsg+0x42/0x100
[ 41.406783] ? sock_recvmsg+0x1d/0x70
[ 41.428201] sock_read_iter+0x84/0xd0
[ 41.445592] ? 0xffffffffa3000000
[ 41.462442] new_sync_read+0x148/0x160
[ 41.479314] ? 0xffffffffa3000000
[ 41.496937] vfs_read+0x138/0x190
[ 41.517198] ksys_read+0x87/0xc0
[ 41.535336] do_syscall_64+0x3b/0x90
[ 41.551637] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 41.568050] RIP: 0033:0x48765b
[ 41.583955] Code: e8 4a 35 fe ff eb 88 cc cc cc cc cc cc cc cc e8 fb 7a fe ff 48 8b 7c 24 10 48 8b 74 24 18 48 8b 54 24 20 48 8b 44 24 08 0f 05 <48> 3d 01 f0 ff ff 76 20 48 c7 44 24 28 ff ff ff ff 48 c7 44 24 30
[ 41.632818] RSP: 002b:000000c000a2f5b8 EFLAGS: 00000212 ORIG_RAX: 0000000000000000
[ 41.664588] RAX: ffffffffffffffda RBX: 000000c000062000 RCX: 000000000048765b
[ 41.681205] RDX: 0000000000005e54 RSI: 000000c000e66000 RDI: 0000000000000016
[ 41.697164] RBP: 000000c000a2f608 R08: 0000000000000001 R09: 00000000000001b4
[ 41.713034] R10: 00000000000000b6 R11: 0000000000000212 R12: 00000000000000e9
[ 41.728755] R13: 0000000000000001 R14: 000000c000a92000 R15: ffffffffffffffff
[ 41.744254] </TASK>
[ 41.758585] Modules linked in: br_netfilter bridge veth netconsole virtio_net
and
[ 33.524802] BUG: Bad page state in process systemd-network pfn:11e60
[ 33.528617] page ffffe05dc0147b00 ffffe05dc04e7a00 ffff8ae9851ec000 (1) len 82 offset 252 metasize 4 hroom 0 hdr_len 12 data ffff8ae9851ec10c data_meta ffff8ae9851ec108 data_end ffff8ae9851ec14e
[ 33.529764] page:000000003792b5ba refcount:0 mapcount:-512 mapping:0000000000000000 index:0x0 pfn:0x11e60
[ 33.532463] flags: 0xfffffc0000000(node=0|zone=1|lastcpupid=0x1fffff)
[ 33.532468] raw: 000fffffc0000000 0000000000000000 dead000000000122 0000000000000000
[ 33.532470] raw: 0000000000000000 0000000000000000 00000000fffffdff 0000000000000000
[ 33.532471] page dumped because: nonzero mapcount
[ 33.532472] Modules linked in: br_netfilter bridge veth netconsole virtio_net
[ 33.532479] CPU: 0 PID: 791 Comm: systemd-network Kdump: loaded Not tainted 5.18.0-rc1+ #37
[ 33.532482] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1.fc35 04/01/2014
[ 33.532484] Call Trace:
[ 33.532496] <TASK>
[ 33.532500] dump_stack_lvl+0x45/0x5a
[ 33.532506] bad_page.cold+0x63/0x94
[ 33.532510] free_pcp_prepare+0x290/0x420
[ 33.532515] free_unref_page+0x1b/0x100
[ 33.532518] skb_release_data+0x13f/0x1c0
[ 33.532524] kfree_skb_reason+0x3e/0xc0
[ 33.532527] ip6_mc_input+0x23c/0x2b0
[ 33.532531] ip6_sublist_rcv_finish+0x83/0x90
[ 33.532534] ip6_sublist_rcv+0x22b/0x2b0
[3] XDP program to reproduce(xdp_pass.c):
#include <linux/bpf.h>
#include <bpf/bpf_helpers.h>
SEC("xdp_pass")
int xdp_pkt_pass(struct xdp_md *ctx)
{
bpf_xdp_adjust_head(ctx, -(int)32);
return XDP_PASS;
}
char _license[] SEC("license") = "GPL";
compile: clang -O2 -g -Wall -target bpf -c xdp_pass.c -o xdp_pass.o
load on virtio_net: ip link set enp1s0 xdpdrv obj xdp_pass.o sec xdp_pass
CC: stable@vger.kernel.org
CC: Jason Wang <jasowang@redhat.com>
CC: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
CC: Daniel Borkmann <daniel@iogearbox.net>
CC: "Michael S. Tsirkin" <mst@redhat.com>
CC: virtualization@lists.linux-foundation.org
Fixes: 8fb7da9e99 ("virtio_net: get build_skb() buf by data ptr")
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Reviewed-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/r/20220425103703.3067292-1-razor@blackwall.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The other port_hidden functions rely on the port_read/port_write
functions to access the hidden control port. These functions apply the
offset for port_base_addr where applicable. Update port_hidden_wait to
use the port_wait_bit so that port_base_addr offsets are accounted for
when waiting for the busy bit to change.
Without the offset the port_hidden_wait function would timeout on
devices that have a non-zero port_base_addr (e.g. MV88E6141), however
devices that have a zero port_base_addr would operate correctly (e.g.
MV88E6390).
Fixes: 609070133a ("net: dsa: mv88e6xxx: update code operating on hidden registers")
Signed-off-by: Nathan Rossi <nathan@nathanrossi.com>
Reviewed-by: Marek Behún <kabel@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Link: https://lore.kernel.org/r/20220425070454.348584-1-nathan@nathanrossi.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Currently, the kernel drops GSO VLAN tagged packet if it's created with
socket(AF_PACKET, SOCK_RAW, 0) plus virtio_net_hdr.
The reason is AF_PACKET doesn't adjust the skb network header if there is
a VLAN tag. Then after virtio_net_hdr_set_proto() called, the skb->protocol
will be set to ETH_P_IP/IPv6. And in later inet/ipv6_gso_segment() the skb
is dropped as network header position is invalid.
Let's handle VLAN packets by adjusting network header position in
packet_parse_headers(). The adjustment is safe and does not affect the
later xmit as tap device also did that.
In packet_snd(), packet_parse_headers() need to be moved before calling
virtio_net_hdr_set_proto(), so we can set correct skb->protocol and
network header first.
There is no need to update tpacket_snd() as it calls packet_parse_headers()
in tpacket_fill_skb(), which is already before calling virtio_net_hdr_*
functions.
skb->no_fcs setting is also moved upper to make all skb settings together
and keep consistency with function packet_sendmsg_spkt().
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Acked-by: Willem de Bruijn <willemb@google.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Link: https://lore.kernel.org/r/20220425014502.985464-1-liuhangbin@gmail.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The hardware checksum offloading requires use of a transmit
status block inserted before the outgoing frame data, this was
updated in '9a9ba2a4aaaa ("net: bcmgenet: always enable status blocks")'
However, skb_tx_timestamp() assumes that it is passed a raw frame
and PTP parsing chokes on this status block.
Fix this by calling __skb_pull(), which hides the TSB before calling
skb_tx_timestamp(), so an outgoing PTP packet is parsed correctly.
As the data in the skb has already been set up for DMA, and the
dma_unmap_* calls use a separately stored address, there is no
no effective change in the data transmission.
Signed-off-by: Jonathan Lemon <jonathan.lemon@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20220424165307.591145-1-jonathan.lemon@gmail.com
Fixes: d03825fba4 ("net: bcmgenet: add skb_tx_timestamp call")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The function mctp_unregister() reclaims the device's relevant resource
when a netcard detaches. However, a running routine may be unaware of
this and cause the use-after-free of the mdev->addrs object.
The race condition can be demonstrated below
cleanup thread another thread
|
unregister_netdev() | mctp_sendmsg()
... | ...
mctp_unregister() | rt = mctp_route_lookup()
... | mctl_local_output()
kfree(mdev->addrs) | ...
| saddr = rt->dev->addrs[0];
|
An attacker can adopt the (recent provided) mtcpserial driver with pty
to fake the device detaching and use the userfaultfd to increase the
race success chance (in mctp_sendmsg). The KASan report for such a POC
is shown below:
[ 86.051955] ==================================================================
[ 86.051955] BUG: KASAN: use-after-free in mctp_local_output+0x4e9/0xb7d
[ 86.051955] Read of size 1 at addr ffff888005f298c0 by task poc/295
[ 86.051955]
[ 86.051955] Call Trace:
[ 86.051955] <TASK>
[ 86.051955] dump_stack_lvl+0x33/0x42
[ 86.051955] print_report.cold.13+0xb2/0x6b3
[ 86.051955] ? preempt_schedule_irq+0x57/0x80
[ 86.051955] ? mctp_local_output+0x4e9/0xb7d
[ 86.051955] kasan_report+0xa5/0x120
[ 86.051955] ? mctp_local_output+0x4e9/0xb7d
[ 86.051955] mctp_local_output+0x4e9/0xb7d
[ 86.051955] ? mctp_dev_set_key+0x79/0x79
[ 86.051955] ? copyin+0x38/0x50
[ 86.051955] ? _copy_from_iter+0x1b6/0xf20
[ 86.051955] ? sysvec_apic_timer_interrupt+0x97/0xb0
[ 86.051955] ? asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 86.051955] ? mctp_local_output+0x1/0xb7d
[ 86.051955] mctp_sendmsg+0x64d/0xdb0
[ 86.051955] ? mctp_sk_close+0x20/0x20
[ 86.051955] ? __fget_light+0x2fd/0x4f0
[ 86.051955] ? mctp_sk_close+0x20/0x20
[ 86.051955] sock_sendmsg+0xdd/0x110
[ 86.051955] __sys_sendto+0x1cc/0x2a0
[ 86.051955] ? __ia32_sys_getpeername+0xa0/0xa0
[ 86.051955] ? new_sync_write+0x335/0x550
[ 86.051955] ? alloc_file+0x22f/0x500
[ 86.051955] ? __ip_do_redirect+0x820/0x1820
[ 86.051955] ? vfs_write+0x44d/0x7b0
[ 86.051955] ? vfs_write+0x44d/0x7b0
[ 86.051955] ? fput_many+0x15/0x120
[ 86.051955] ? ksys_write+0x155/0x1b0
[ 86.051955] ? __ia32_sys_read+0xa0/0xa0
[ 86.051955] __x64_sys_sendto+0xd8/0x1b0
[ 86.051955] ? exit_to_user_mode_prepare+0x2f/0x120
[ 86.051955] ? syscall_exit_to_user_mode+0x12/0x20
[ 86.051955] do_syscall_64+0x3a/0x80
[ 86.051955] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 86.051955] RIP: 0033:0x7f82118a56b3
[ 86.051955] RSP: 002b:00007ffdb154b110 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
[ 86.051955] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f82118a56b3
[ 86.051955] RDX: 0000000000000010 RSI: 00007f8211cd4000 RDI: 0000000000000007
[ 86.051955] RBP: 00007ffdb154c1d0 R08: 00007ffdb154b164 R09: 000000000000000c
[ 86.051955] R10: 0000000000000000 R11: 0000000000000293 R12: 000055d779800db0
[ 86.051955] R13: 00007ffdb154c2b0 R14: 0000000000000000 R15: 0000000000000000
[ 86.051955] </TASK>
[ 86.051955]
[ 86.051955] Allocated by task 295:
[ 86.051955] kasan_save_stack+0x1c/0x40
[ 86.051955] __kasan_kmalloc+0x84/0xa0
[ 86.051955] mctp_rtm_newaddr+0x242/0x610
[ 86.051955] rtnetlink_rcv_msg+0x2fd/0x8b0
[ 86.051955] netlink_rcv_skb+0x11c/0x340
[ 86.051955] netlink_unicast+0x439/0x630
[ 86.051955] netlink_sendmsg+0x752/0xc00
[ 86.051955] sock_sendmsg+0xdd/0x110
[ 86.051955] __sys_sendto+0x1cc/0x2a0
[ 86.051955] __x64_sys_sendto+0xd8/0x1b0
[ 86.051955] do_syscall_64+0x3a/0x80
[ 86.051955] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 86.051955]
[ 86.051955] Freed by task 301:
[ 86.051955] kasan_save_stack+0x1c/0x40
[ 86.051955] kasan_set_track+0x21/0x30
[ 86.051955] kasan_set_free_info+0x20/0x30
[ 86.051955] __kasan_slab_free+0x104/0x170
[ 86.051955] kfree+0x8c/0x290
[ 86.051955] mctp_dev_notify+0x161/0x2c0
[ 86.051955] raw_notifier_call_chain+0x8b/0xc0
[ 86.051955] unregister_netdevice_many+0x299/0x1180
[ 86.051955] unregister_netdevice_queue+0x210/0x2f0
[ 86.051955] unregister_netdev+0x13/0x20
[ 86.051955] mctp_serial_close+0x6d/0xa0
[ 86.051955] tty_ldisc_kill+0x31/0xa0
[ 86.051955] tty_ldisc_hangup+0x24f/0x560
[ 86.051955] __tty_hangup.part.28+0x2ce/0x6b0
[ 86.051955] tty_release+0x327/0xc70
[ 86.051955] __fput+0x1df/0x8b0
[ 86.051955] task_work_run+0xca/0x150
[ 86.051955] exit_to_user_mode_prepare+0x114/0x120
[ 86.051955] syscall_exit_to_user_mode+0x12/0x20
[ 86.051955] do_syscall_64+0x46/0x80
[ 86.051955] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 86.051955]
[ 86.051955] The buggy address belongs to the object at ffff888005f298c0
[ 86.051955] which belongs to the cache kmalloc-8 of size 8
[ 86.051955] The buggy address is located 0 bytes inside of
[ 86.051955] 8-byte region [ffff888005f298c0, ffff888005f298c8)
[ 86.051955]
[ 86.051955] The buggy address belongs to the physical page:
[ 86.051955] flags: 0x100000000000200(slab|node=0|zone=1)
[ 86.051955] raw: 0100000000000200 dead000000000100 dead000000000122 ffff888005c42280
[ 86.051955] raw: 0000000000000000 0000000080660066 00000001ffffffff 0000000000000000
[ 86.051955] page dumped because: kasan: bad access detected
[ 86.051955]
[ 86.051955] Memory state around the buggy address:
[ 86.051955] ffff888005f29780: 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00
[ 86.051955] ffff888005f29800: fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc
[ 86.051955] >ffff888005f29880: fc fc fc fb fc fc fc fc fa fc fc fc fc fa fc fc
[ 86.051955] ^
[ 86.051955] ffff888005f29900: fc fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc
[ 86.051955] ffff888005f29980: fc 00 fc fc fc fc 00 fc fc fc fc 00 fc fc fc fc
[ 86.051955] ==================================================================
To this end, just like the commit e04480920d ("Bluetooth: defer
cleanup of resources in hci_unregister_dev()") this patch defers the
destructive kfree(mdev->addrs) in mctp_unregister to the mctp_dev_put,
where the refcount of mdev is zero and the entire device is reclaimed.
This prevents the use-after-free because the sendmsg thread holds the
reference of mdev in the mctp_route object.
Fixes: 583be982d9 (mctp: Add device handling and netlink interface)
Signed-off-by: Lin Ma <linma@zju.edu.cn>
Acked-by: Jeremy Kerr <jk@codeconstruct.com.au>
Link: https://lore.kernel.org/r/20220422114340.32346-1-linma@zju.edu.cn
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
It's noted that dcvs interrupts are not self-clearing, thus an interrupt
handler runs constantly, which leads to a severe regression in runtime.
To fix the problem an explicit write to clear interrupt register is
required, note that on OSM platforms the register may not be present.
Fixes: 275157b367 ("cpufreq: qcom-cpufreq-hw: Add dcvs interrupt support")
Signed-off-by: Vladimir Zapolskiy <vladimir.zapolskiy@linaro.org>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Kumar Kartikeya Dwivedi says:
====================
This set enables storing pointers of a certain type in BPF map, and extends the
verifier to enforce type safety and lifetime correctness properties.
The infrastructure being added is generic enough for allowing storing any kind
of pointers whose type is available using BTF (user or kernel) in the future
(e.g. strongly typed memory allocation in BPF program), which are internally
tracked in the verifier as PTR_TO_BTF_ID, but for now the series limits them to
two kinds of pointers obtained from the kernel.
Obviously, use of this feature depends on map BTF.
1. Unreferenced kernel pointer
In this case, there are very few restrictions. The pointer type being stored
must match the type declared in the map value. However, such a pointer when
loaded from the map can only be dereferenced, but not passed to any in-kernel
helpers or kernel functions available to the program. This is because while the
verifier's exception handling mechanism coverts BPF_LDX to PROBE_MEM loads,
which are then handled specially by the JIT implementation, the same liberty is
not available to accesses inside the kernel. The pointer by the time it is
passed into a helper has no lifetime related guarantees about the object it is
pointing to, and may well be referencing invalid memory.
2. Referenced kernel pointer
This case imposes a lot of restrictions on the programmer, to ensure safety. To
transfer the ownership of a reference in the BPF program to the map, the user
must use the bpf_kptr_xchg helper, which returns the old pointer contained in
the map, as an acquired reference, and releases verifier state for the
referenced pointer being exchanged, as it moves into the map.
This a normal PTR_TO_BTF_ID that can be used with in-kernel helpers and kernel
functions callable by the program.
However, if BPF_LDX is used to load a referenced pointer from the map, it is
still not permitted to pass it to in-kernel helpers or kernel functions. To
obtain a reference usable with helpers, the user must invoke a kfunc helper
which returns a usable reference (which also must be eventually released before
BPF_EXIT, or moved into a map).
Since the load of the pointer (preserving data dependency ordering) must happen
inside the RCU read section, the kfunc helper will take a pointer to the map
value, which must point to the actual pointer of the object whose reference is
to be raised. The type will be verified from the BTF information of the kfunc,
as the prototype must be:
T *func(T **, ... /* other arguments */);
Then, the verifier checks whether pointer at offset of the map value points to
the type T, and permits the call.
This convention is followed so that such helpers may also be called from
sleepable BPF programs, where RCU read lock is not necessarily held in the BPF
program context, hence necessiating the need to pass in a pointer to the actual
pointer to perform the load inside the RCU read section.
Notes
-----
* C selftests require https://reviews.llvm.org/D119799 to pass.
* Unlike BPF timers, kptr is not reset or freed on map_release_uref.
* Referenced kptr storage is always treated as unsigned long * on kernel side,
as BPF side cannot mutate it. The storage (8 bytes) is sufficient for both
32-bit and 64-bit platforms.
* Use of WRITE_ONCE to reset unreferenced kptr on 32-bit systems is fine, as
the actual pointer is always word sized, so the store tearing into two 32-bit
stores won't be a problem as the other half is always zeroed out.
Changelog:
----------
v5 -> v6
v5: https://lore.kernel.org/bpf/20220415160354.1050687-1-memxor@gmail.com
* Address comments from Alexei
* Drop 'Revisit stack usage' comment
* Rename off_btf to kernel_btf
* Add comment about searching using type from map BTF
* Do kmemdup + btf_get instead of get + kmemdup + put
* Add comment for btf_struct_ids_match
* Add comment for assigning non-zero id for mark_ptr_or_null_reg
* Rename PTR_RELEASE to OBJ_RELEASE
* Rename BPF_MAP_OFF_DESC_TYPE_XXX_KPTR to BPF_KPTR_XXX
* Remove unneeded likely/unlikely in cold functions
* Fix other misc nits
* Keep release_regno instead of replacing with bool + regno
* Add a patch to prevent type match for first member when off == 0 for
release functions (kfunc + BPF helpers)
* Guard kptr/kptr_ref definition in libbpf header with __has_attribute
to prevent selftests compilation error with old clang not support
type tags
v4 -> v5
v4: https://lore.kernel.org/bpf/20220409093303.499196-1-memxor@gmail.com
* Address comments from Joanne
* Move __btf_member_bit_offset before strcmp
* Move strcmp conditional on name to unref kptr patch
* Directly return from btf_find_struct in patch 1
* Use enum btf_field_type vs int field_type
* Put btf and btf_id in off_desc in named struct 'kptr'
* Switch order for BTF_FIELD_IGNORE check
* Drop dead tab->nr_off = 0 store
* Use i instead of tab->nr_off to btf_put on failure
* Replace kzalloc + memcpy with kmemdup (kernel test robot)
* Reject both BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG
* Add logging statement for reject BPF_MODE(insn->code) != BPF_MEM
* Rename off_desc -> kptr_off_desc in check_mem_access
* Drop check for err, fallthrough to end of function
* Remove is_release_function, use meta.release_regno to detect release
function, release reference state, and remove check_release_regno
* Drop off_desc->flags, use off_desc->type
* Update comment for ARG_PTR_TO_KPTR
* Distinguish between direct/indirect access to kptr
* Drop check_helper_mem_access from process_kptr_func, check_mem_reg in kptr_get
* Add verifier test for helper accessing kptr indirectly
* Fix other misc nits, add Acked-by for patch 2
v3 -> v4
v3: https://lore.kernel.org/bpf/20220320155510.671497-1-memxor@gmail.com
* Use btf_parse_kptrs, plural kptrs naming (Joanne, Andrii)
* Remove unused parameters in check_map_kptr_access (Joanne)
* Handle idx < info_cnt kludge using tmp variable (Andrii)
* Validate tags always precede modifiers in BTF (Andrii)
* Split out into https://lore.kernel.org/bpf/20220406004121.282699-1-memxor@gmail.com
* Store u32 type_id in btf_field_info (Andrii)
* Use base_type in map_kptr_match_type (Andrii)
* Free kptr_off_tab when not bpf_capable (Martin)
* Use PTR_RELEASE flag instead of bools in bpf_func_proto (Joanne)
* Drop extra reg->off and reg->ref_obj_id checks in map_kptr_match_type (Martin)
* Use separate u32 and u8 arrays for offs and sizes in off_arr (Andrii)
* Simplify and remove map->value_size sentinel in copy_map_value (Andrii)
* Use sort_r to keep both arrays in sync while sorting (Andrii)
* Rename check_and_free_timers_and_kptr to check_and_free_fields (Andrii)
* Move dtor prototype checks to registration phase (Alexei)
* Use ret variable for checking ASSERT_XXX, use shorter strings (Andrii)
* Fix missing checks for other maps (Jiri)
* Fix various other nits, and bugs noticed during self review
v2 -> v3
v2: https://lore.kernel.org/bpf/20220317115957.3193097-1-memxor@gmail.com
* Address comments from Alexei
* Set name, sz, align in btf_find_field
* Do idx >= info_cnt check in caller of btf_find_field_*
* Use extra element in the info_arr to make this safe
* Remove while loop, reject extra tags
* Remove cases of defensive programming
* Move bpf_capable() check to map_check_btf
* Put check_ptr_off_reg reordering hunk into separate patch
* Warn for ref_ptr once
* Make the meta.ref_obj_id == 0 case simpler to read
* Remove kptr_percpu and kptr_user support, remove their tests
* Store size of field at offset in off_arr
* Fix BPF_F_NO_PREALLOC set wrongly for hash map in C selftest
* Add missing check_mem_reg call for kptr_get kfunc arg#0 check
v1 -> v2
v1: https://lore.kernel.org/bpf/20220220134813.3411982-1-memxor@gmail.com
* Address comments from Alexei
* Rename bpf_btf_find_by_name_kind_all to bpf_find_btf_id
* Reduce indentation level in that function
* Always take reference regardless of module or vmlinux BTF
* Also made it the same for btf_get_module_btf
* Use kptr, kptr_ref, kptr_percpu, kptr_user type tags
* Don't reserve tag namespace
* Refactor btf_find_field to be side effect free, allocate and populate
kptr_off_tab in caller
* Move module reference to dtor patch
* Remove support for BPF_XCHG, BPF_CMPXCHG insn
* Introduce bpf_kptr_xchg helper
* Embed offset array in struct bpf_map, populate and sort it once
* Adjust copy_map_value to memcpy directly using this offset array
* Removed size member from offset array to save space
* Fix some problems pointed out by kernel test robot
* Tidy selftests
* Lots of other minor fixes
====================
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
This uses the __kptr and __kptr_ref macros as well, and tries to test
the stuff that is supposed to work, since we have negative tests in
test_verifier suite. Also include some code to test map-in-map support,
such that the inner_map_meta matches the kptr_off_tab of map added as
element.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-12-memxor@gmail.com
The current of behavior of btf_struct_ids_match for release arguments is
that when type match fails, it retries with first member type again
(recursively). Since the offset is already 0, this is akin to just
casting the pointer in normal C, since if type matches it was just
embedded inside parent sturct as an object. However, we want to reject
cases for release function type matching, be it kfunc or BPF helpers.
An example is the following:
struct foo {
struct bar b;
};
struct foo *v = acq_foo();
rel_bar(&v->b); // btf_struct_ids_match fails btf_types_are_same, then
// retries with first member type and succeeds, while
// it should fail.
Hence, don't walk the struct and only rely on btf_types_are_same for
strict mode. All users of strict mode must be dealing with zero offset
anyway, since otherwise they would want the struct to be walked.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-10-memxor@gmail.com
We introduce a new style of kfunc helpers, namely *_kptr_get, where they
take pointer to the map value which points to a referenced kernel
pointer contained in the map. Since this is referenced, only
bpf_kptr_xchg from BPF side and xchg from kernel side is allowed to
change the current value, and each pointer that resides in that location
would be referenced, and RCU protected (this must be kept in mind while
adding kernel types embeddable as reference kptr in BPF maps).
This means that if do the load of the pointer value in an RCU read
section, and find a live pointer, then as long as we hold RCU read lock,
it won't be freed by a parallel xchg + release operation. This allows us
to implement a safe refcount increment scheme. Hence, enforce that first
argument of all such kfunc is a proper PTR_TO_MAP_VALUE pointing at the
right offset to referenced pointer.
For the rest of the arguments, they are subjected to typical kfunc
argument checks, hence allowing some flexibility in passing more intent
into how the reference should be taken.
For instance, in case of struct nf_conn, it is not freed until RCU grace
period ends, but can still be reused for another tuple once refcount has
dropped to zero. Hence, a bpf_ct_kptr_get helper not only needs to call
refcount_inc_not_zero, but also do a tuple match after incrementing the
reference, and when it fails to match it, put the reference again and
return NULL.
This can be implemented easily if we allow passing additional parameters
to the bpf_ct_kptr_get kfunc, like a struct bpf_sock_tuple * and a
tuple__sz pair.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-9-memxor@gmail.com
A destructor kfunc can be defined as void func(type *), where type may
be void or any other pointer type as per convenience.
In this patch, we ensure that the type is sane and capture the function
pointer into off_desc of ptr_off_tab for the specific pointer offset,
with the invariant that the dtor pointer is always set when 'kptr_ref'
tag is applied to the pointer's pointee type, which is indicated by the
flag BPF_MAP_VALUE_OFF_F_REF.
Note that only BTF IDs whose destructor kfunc is registered, thus become
the allowed BTF IDs for embedding as referenced kptr. Hence it serves
the purpose of finding dtor kfunc BTF ID, as well acting as a check
against the whitelist of allowed BTF IDs for this purpose.
Finally, wire up the actual freeing of the referenced pointer if any at
all available offsets, so that no references are leaked after the BPF
map goes away and the BPF program previously moved the ownership a
referenced pointer into it.
The behavior is similar to BPF timers, where bpf_map_{update,delete}_elem
will free any existing referenced kptr. The same case is with LRU map's
bpf_lru_push_free/htab_lru_push_free functions, which are extended to
reset unreferenced and free referenced kptr.
Note that unlike BPF timers, kptr is not reset or freed when map uref
drops to zero.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-8-memxor@gmail.com
To support storing referenced PTR_TO_BTF_ID in maps, we require
associating a specific BTF ID with a 'destructor' kfunc. This is because
we need to release a live referenced pointer at a certain offset in map
value from the map destruction path, otherwise we end up leaking
resources.
Hence, introduce support for passing an array of btf_id, kfunc_btf_id
pairs that denote a BTF ID and its associated release function. Then,
add an accessor 'btf_find_dtor_kfunc' which can be used to look up the
destructor kfunc of a certain BTF ID. If found, we can use it to free
the object from the map free path.
The registration of these pairs also serve as a whitelist of structures
which are allowed as referenced PTR_TO_BTF_ID in a BPF map, because
without finding the destructor kfunc, we will bail and return an error.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-7-memxor@gmail.com
Since now there might be at most 10 offsets that need handling in
copy_map_value, the manual shuffling and special case is no longer going
to work. Hence, let's generalise the copy_map_value function by using
a sorted array of offsets to skip regions that must be avoided while
copying into and out of a map value.
When the map is created, we populate the offset array in struct map,
Then, copy_map_value uses this sorted offset array is used to memcpy
while skipping timer, spin lock, and kptr. The array is allocated as
in most cases none of these special fields would be present in map
value, hence we can save on space for the common case by not embedding
the entire object inside bpf_map struct.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-6-memxor@gmail.com
While we can guarantee that even for unreferenced kptr, the object
pointer points to being freed etc. can be handled by the verifier's
exception handling (normal load patching to PROBE_MEM loads), we still
cannot allow the user to pass these pointers to BPF helpers and kfunc,
because the same exception handling won't be done for accesses inside
the kernel. The same is true if a referenced pointer is loaded using
normal load instruction. Since the reference is not guaranteed to be
held while the pointer is used, it must be marked as untrusted.
Hence introduce a new type flag, PTR_UNTRUSTED, which is used to mark
all registers loading unreferenced and referenced kptr from BPF maps,
and ensure they can never escape the BPF program and into the kernel by
way of calling stable/unstable helpers.
In check_ptr_to_btf_access, the !type_may_be_null check to reject type
flags is still correct, as apart from PTR_MAYBE_NULL, only MEM_USER,
MEM_PERCPU, and PTR_UNTRUSTED may be set for PTR_TO_BTF_ID. The first
two are checked inside the function and rejected using a proper error
message, but we still want to allow dereference of untrusted case.
Also, we make sure to inherit PTR_UNTRUSTED when chain of pointers are
walked, so that this flag is never dropped once it has been set on a
PTR_TO_BTF_ID (i.e. trusted to untrusted transition can only be in one
direction).
In convert_ctx_accesses, extend the switch case to consider untrusted
PTR_TO_BTF_ID in addition to normal PTR_TO_BTF_ID for PROBE_MEM
conversion for BPF_LDX.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-5-memxor@gmail.com
Extending the code in previous commits, introduce referenced kptr
support, which needs to be tagged using 'kptr_ref' tag instead. Unlike
unreferenced kptr, referenced kptr have a lot more restrictions. In
addition to the type matching, only a newly introduced bpf_kptr_xchg
helper is allowed to modify the map value at that offset. This transfers
the referenced pointer being stored into the map, releasing the
references state for the program, and returning the old value and
creating new reference state for the returned pointer.
Similar to unreferenced pointer case, return value for this case will
also be PTR_TO_BTF_ID_OR_NULL. The reference for the returned pointer
must either be eventually released by calling the corresponding release
function, otherwise it must be transferred into another map.
It is also allowed to call bpf_kptr_xchg with a NULL pointer, to clear
the value, and obtain the old value if any.
BPF_LDX, BPF_STX, and BPF_ST cannot access referenced kptr. A future
commit will permit using BPF_LDX for such pointers, but attempt at
making it safe, since the lifetime of object won't be guaranteed.
There are valid reasons to enforce the restriction of permitting only
bpf_kptr_xchg to operate on referenced kptr. The pointer value must be
consistent in face of concurrent modification, and any prior values
contained in the map must also be released before a new one is moved
into the map. To ensure proper transfer of this ownership, bpf_kptr_xchg
returns the old value, which the verifier would require the user to
either free or move into another map, and releases the reference held
for the pointer being moved in.
In the future, direct BPF_XCHG instruction may also be permitted to work
like bpf_kptr_xchg helper.
Note that process_kptr_func doesn't have to call
check_helper_mem_access, since we already disallow rdonly/wronly flags
for map, which is what check_map_access_type checks, and we already
ensure the PTR_TO_MAP_VALUE refers to kptr by obtaining its off_desc,
so check_map_access is also not required.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-4-memxor@gmail.com
Add a new type flag for bpf_arg_type that when set tells verifier that
for a release function, that argument's register will be the one for
which meta.ref_obj_id will be set, and which will then be released
using release_reference. To capture the regno, introduce a new field
release_regno in bpf_call_arg_meta.
This would be required in the next patch, where we may either pass NULL
or a refcounted pointer as an argument to the release function
bpf_kptr_xchg. Just releasing only when meta.ref_obj_id is set is not
enough, as there is a case where the type of argument needed matches,
but the ref_obj_id is set to 0. Hence, we must enforce that whenever
meta.ref_obj_id is zero, the register that is to be released can only
be NULL for a release function.
Since we now indicate whether an argument is to be released in
bpf_func_proto itself, is_release_function helper has lost its utitlity,
hence refactor code to work without it, and just rely on
meta.release_regno to know when to release state for a ref_obj_id.
Still, the restriction of one release argument and only one ref_obj_id
passed to BPF helper or kfunc remains. This may be lifted in the future.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-3-memxor@gmail.com
This commit introduces a new pointer type 'kptr' which can be embedded
in a map value to hold a PTR_TO_BTF_ID stored by a BPF program during
its invocation. When storing such a kptr, BPF program's PTR_TO_BTF_ID
register must have the same type as in the map value's BTF, and loading
a kptr marks the destination register as PTR_TO_BTF_ID with the correct
kernel BTF and BTF ID.
Such kptr are unreferenced, i.e. by the time another invocation of the
BPF program loads this pointer, the object which the pointer points to
may not longer exist. Since PTR_TO_BTF_ID loads (using BPF_LDX) are
patched to PROBE_MEM loads by the verifier, it would safe to allow user
to still access such invalid pointer, but passing such pointers into
BPF helpers and kfuncs should not be permitted. A future patch in this
series will close this gap.
The flexibility offered by allowing programs to dereference such invalid
pointers while being safe at runtime frees the verifier from doing
complex lifetime tracking. As long as the user may ensure that the
object remains valid, it can ensure data read by it from the kernel
object is valid.
The user indicates that a certain pointer must be treated as kptr
capable of accepting stores of PTR_TO_BTF_ID of a certain type, by using
a BTF type tag 'kptr' on the pointed to type of the pointer. Then, this
information is recorded in the object BTF which will be passed into the
kernel by way of map's BTF information. The name and kind from the map
value BTF is used to look up the in-kernel type, and the actual BTF and
BTF ID is recorded in the map struct in a new kptr_off_tab member. For
now, only storing pointers to structs is permitted.
An example of this specification is shown below:
#define __kptr __attribute__((btf_type_tag("kptr")))
struct map_value {
...
struct task_struct __kptr *task;
...
};
Then, in a BPF program, user may store PTR_TO_BTF_ID with the type
task_struct into the map, and then load it later.
Note that the destination register is marked PTR_TO_BTF_ID_OR_NULL, as
the verifier cannot know whether the value is NULL or not statically, it
must treat all potential loads at that map value offset as loading a
possibly NULL pointer.
Only BPF_LDX, BPF_STX, and BPF_ST (with insn->imm = 0 to denote NULL)
are allowed instructions that can access such a pointer. On BPF_LDX, the
destination register is updated to be a PTR_TO_BTF_ID, and on BPF_STX,
it is checked whether the source register type is a PTR_TO_BTF_ID with
same BTF type as specified in the map BTF. The access size must always
be BPF_DW.
For the map in map support, the kptr_off_tab for outer map is copied
from the inner map's kptr_off_tab. It was chosen to do a deep copy
instead of introducing a refcount to kptr_off_tab, because the copy only
needs to be done when paramterizing using inner_map_fd in the map in map
case, hence would be unnecessary for all other users.
It is not permitted to use MAP_FREEZE command and mmap for BPF map
having kptrs, similar to the bpf_timer case. A kptr also requires that
BPF program has both read and write access to the map (hence both
BPF_F_RDONLY_PROG and BPF_F_WRONLY_PROG are disallowed).
Note that check_map_access must be called from both
check_helper_mem_access and for the BPF instructions, hence the kptr
check must distinguish between ACCESS_DIRECT and ACCESS_HELPER, and
reject ACCESS_HELPER cases. We rename stack_access_src to bpf_access_src
and reuse it for this purpose.
Signed-off-by: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220424214901.2743946-2-memxor@gmail.com
Rename bpf_prog_run_array_cg_flags to bpf_prog_run_array_cg and
use it everywhere. check_return_code already enforces sane
return ranges for all cgroup types. (only egress and bind hooks have
uncanonical return ranges, the rest is using [0, 1])
No functional changes.
v2:
- 'func_ret & 1' under explicit test (Andrii & Martin)
Suggested-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/20220425220448.3669032-1-sdf@google.com
Commit 493bc90a96 ("at86rf230: add debugfs support") brought trac
support as part of a debugfs feature, in order to add some testing
capabilities involving ack handling.
As we want to collect trac errors but do not need the debugfs feature
anymore, let's partially revert this commit, keeping the Tx trac
handling part which still makes sense. This allows to always return the
trac error directly to the core with the recently introduced
ieee802154_xmit_error() helper.
Suggested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220407100903.1695973-8-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
If we end up at this location, it means that there was likely a hardware
issue (either a bus error when asynchronously offloading the packet to
the transceiver, or the transceiver took too long for some state
change). In this case it was decided to return IEEE802154_SYSTEM_ERROR
through the ieee802154_xmit_hw_error() helper dedicated to non
IEEE802.15.4 specific errors.
Let's use this helper instead of (almost) open-coding it.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220407100903.1695973-7-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
A few drivers do the full transmit operation asynchronously, which means
that a bus error that happens when forwarding the packet to the
transmitter or a timeout happening when offloading the request to the
transmitter will not be reported immediately.
The solution in this case is to call this new helper to free the
necessary resources, restart the queue and always return the same
generic TRAC error code: IEEE802154_SYSTEM_ERROR.
Suggested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220407100903.1695973-6-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
So far there is only a helper for successful transmissions, which led
device drivers to implement their own handling in case of
error. Unfortunately, we really need all the drivers to give the hand
back to the core once they are done in order to be able to build a
proper synchronous API. So let's create a _xmit_error() helper and take
this opportunity to fill the new device-global field storing Tx
statuses.
Suggested-by: Alexander Aring <alex.aring@gmail.com>
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220407100903.1695973-5-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
So far no error is returned from a failing transmission. However it
might sometimes be useful, and particularly easy to use during sync
transfers (for certain MLME commands). Let's create an internal variable
for that, global to the device. Right now only success are registered,
which is rather useless, but soon we will have more situations filling
this field.
Signed-off-by: Miquel Raynal <miquel.raynal@bootlin.com>
Acked-by: Alexander Aring <aahringo@redhat.com>
Link: https://lore.kernel.org/r/20220407100903.1695973-4-miquel.raynal@bootlin.com
Signed-off-by: Stefan Schmidt <stefan@datenfreihafen.org>
Since version 5.13, the standard syscon bindings have been added
to all clps711x DT nodes, so we can now use the more general
syscon_regmap_lookup_by_phandle function to get the syscon pointer.
Signed-off-by: Alexander Shiyan <eagle.alexander923@gmail.com>
Signed-off-by: Helge Deller <deller@gmx.de>
Wen Gu says:
====================
net/smc: Two fixes for smc fallback
This patch set includes two fixes for smc fallback:
Patch 1/2 introduces some simple helpers to wrap the replacement
and restore of clcsock's callback functions. Make sure that only
the original callbacks will be saved and not overwritten.
Patch 2/2 fixes a syzbot reporting slab-out-of-bound issue where
smc_fback_error_report() accesses the already freed smc sock (see
https://lore.kernel.org/r/00000000000013ca8105d7ae3ada@google.com/).
The patch fixes it by resetting sk_user_data and restoring clcsock
callback functions timely in fallback situation.
But it should be noted that although patch 2/2 can fix the issue
of 'slab-out-of-bounds/use-after-free in smc_fback_error_report',
it can't pass the syzbot reproducer test. Because after applying
these two patches in upstream, syzbot reproducer triggered another
known issue like this:
==================================================================
BUG: KASAN: use-after-free in tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511
Read of size 8 at addr ffff888020328380 by task udevd/4158
CPU: 1 PID: 4158 Comm: udevd Not tainted 5.18.0-rc3-syzkaller-00074-gb05a5683eba6-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
<IRQ>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_address_description.constprop.0.cold+0xeb/0x467 mm/kasan/report.c:313
print_report mm/kasan/report.c:429 [inline]
kasan_report.cold+0xf4/0x1c6 mm/kasan/report.c:491
tcp_retransmit_timer+0x2ef3/0x3360 net/ipv4/tcp_timer.c:511
tcp_write_timer_handler+0x5e6/0xbc0 net/ipv4/tcp_timer.c:622
tcp_write_timer+0xa2/0x2b0 net/ipv4/tcp_timer.c:642
call_timer_fn+0x1a5/0x6b0 kernel/time/timer.c:1421
expire_timers kernel/time/timer.c:1466 [inline]
__run_timers.part.0+0x679/0xa80 kernel/time/timer.c:1737
__run_timers kernel/time/timer.c:1715 [inline]
run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1750
__do_softirq+0x29b/0x9c2 kernel/softirq.c:558
invoke_softirq kernel/softirq.c:432 [inline]
__irq_exit_rcu+0x123/0x180 kernel/softirq.c:637
irq_exit_rcu+0x5/0x20 kernel/softirq.c:649
sysvec_apic_timer_interrupt+0x93/0xc0 arch/x86/kernel/apic/apic.c:1097
</IRQ>
...
(detail report can be found in https://syzkaller.appspot.com/text?tag=CrashReport&x=15406b44f00000)
IMHO, the above issue is the same as this known one: https://syzkaller.appspot.com/bug?extid=694120e1002c117747ed,
and it doesn't seem to be related with SMC. The discussion about this known issue is ongoing and can be found in
https://lore.kernel.org/bpf/000000000000f75af905d3ba0716@google.com/T/.
And I added the temporary solution mentioned in the above discussion on
top of my two patches, the syzbot reproducer of 'slab-out-of-bounds/
use-after-free in smc_fback_error_report' no longer triggers any issue.
====================
Link: https://lore.kernel.org/r/1650614179-11529-1-git-send-email-guwen@linux.alibaba.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
syzbot reported a slab-out-of-bounds/use-after-free issue,
which was caused by accessing an already freed smc sock in
fallback-specific callback functions of clcsock.
This patch fixes the issue by restoring fallback-specific
callback functions to original ones and resetting clcsock
sk_user_data to NULL before freeing smc sock.
Meanwhile, this patch introduces sk_callback_lock to make
the access and assignment to sk_user_data mutually exclusive.
Reported-by: syzbot+b425899ed22c6943e00b@syzkaller.appspotmail.com
Fixes: 341adeec9a ("net/smc: Forward wakeup to smc socket waitqueue after fallback")
Link: https://lore.kernel.org/r/00000000000013ca8105d7ae3ada@google.com/
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Both listen and fallback process will save the current clcsock
callback functions and establish new ones. But if both of them
happen, the saved callback functions will be overwritten.
So this patch introduces some helpers to ensure that only save
the original callback functions of clcsock.
Fixes: 341adeec9a ("net/smc: Forward wakeup to smc socket waitqueue after fallback")
Signed-off-by: Wen Gu <guwen@linux.alibaba.com>
Acked-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Pull f2fs fixes from Jaegeuk Kim:
"This includes major bug fixes introduced in 5.18-rc1 and 5.17+:
- Remove obsolete whint_mode (5.18-rc1)
- Fix IO split issue caused by op_flags change in f2fs (5.18-rc1)
- Fix a wrong condition check to detect IO failure loop (5.18-rc1)
- Fix wrong data truncation during roll-forward (5.17+)"
* tag 'f2fs-fix-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs:
f2fs: should not truncate blocks during roll-forward recovery
f2fs: fix wrong condition check when failing metapage read
f2fs: keep io_flags to avoid IO split due to different op_flags in two fio holders
f2fs: remove obsolete whint_mode
This is a driver for pureLiFi X, XL, XC devices which use light to transmit
data, so they are not compatible with normal Wi-Fi devices. The driver uses
separate NL80211_BAND_LC band to distinguish from Wi-Fi. The driver is based
on 802.11 softMAC Architecture and uses native 802.11 for configuration and
management. Station and Ad-Hoc modes are supported.
The driver is compiled and tested in ARM, x86 architectures and compiled in
powerpc architecture. This driver implementation has been based on the zd1211rw
driver.
Signed-off-by: Srinivasan Raju <srini.raju@purelifi.com>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/20220224182042.132466-3-srini.raju@purelifi.com
Reduce a number of included headers to a necessary minimum.
Signed-off-by: Marcin Wojtas <mw@semihalf.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
