linux/include
Eric Dumazet 3a415d59c1 net/sched: sch_taprio: fix possible use-after-free
syzbot reported a nasty crash [1] in net_tx_action() which
made little sense until we got a repro.

This repro installs a taprio qdisc, but providing an
invalid TCA_RATE attribute.

qdisc_create() has to destroy the just initialized
taprio qdisc, and taprio_destroy() is called.

However, the hrtimer used by taprio had already fired,
therefore advance_sched() called __netif_schedule().

Then net_tx_action was trying to use a destroyed qdisc.

We can not undo the __netif_schedule(), so we must wait
until one cpu serviced the qdisc before we can proceed.

Many thanks to Alexander Potapenko for his help.

[1]
BUG: KMSAN: uninit-value in queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
BUG: KMSAN: uninit-value in do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
BUG: KMSAN: uninit-value in __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
BUG: KMSAN: uninit-value in _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
 queued_spin_trylock include/asm-generic/qspinlock.h:94 [inline]
 do_raw_spin_trylock include/linux/spinlock.h:191 [inline]
 __raw_spin_trylock include/linux/spinlock_api_smp.h:89 [inline]
 _raw_spin_trylock+0x92/0xa0 kernel/locking/spinlock.c:138
 spin_trylock include/linux/spinlock.h:359 [inline]
 qdisc_run_begin include/net/sch_generic.h:187 [inline]
 qdisc_run+0xee/0x540 include/net/pkt_sched.h:125
 net_tx_action+0x77c/0x9a0 net/core/dev.c:5086
 __do_softirq+0x1cc/0x7fb kernel/softirq.c:571
 run_ksoftirqd+0x2c/0x50 kernel/softirq.c:934
 smpboot_thread_fn+0x554/0x9f0 kernel/smpboot.c:164
 kthread+0x31b/0x430 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:732 [inline]
 slab_alloc_node mm/slub.c:3258 [inline]
 __kmalloc_node_track_caller+0x814/0x1250 mm/slub.c:4970
 kmalloc_reserve net/core/skbuff.c:358 [inline]
 __alloc_skb+0x346/0xcf0 net/core/skbuff.c:430
 alloc_skb include/linux/skbuff.h:1257 [inline]
 nlmsg_new include/net/netlink.h:953 [inline]
 netlink_ack+0x5f3/0x12b0 net/netlink/af_netlink.c:2436
 netlink_rcv_skb+0x55d/0x6c0 net/netlink/af_netlink.c:2507
 rtnetlink_rcv+0x30/0x40 net/core/rtnetlink.c:6108
 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline]
 netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345
 netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 ____sys_sendmsg+0xabc/0xe90 net/socket.c:2482
 ___sys_sendmsg+0x2a1/0x3f0 net/socket.c:2536
 __sys_sendmsg net/socket.c:2565 [inline]
 __do_sys_sendmsg net/socket.c:2574 [inline]
 __se_sys_sendmsg net/socket.c:2572 [inline]
 __x64_sys_sendmsg+0x367/0x540 net/socket.c:2572
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 0 PID: 13 Comm: ksoftirqd/0 Not tainted 6.0.0-rc2-syzkaller-47461-gac3859c02d7f #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/22/2022

Fixes: 5a781ccbd1 ("tc: Add support for configuring the taprio scheduler")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2023-01-16 13:25:34 +00:00
..
acpi ACPI: video: Allow GPU drivers to report no panels 2022-12-22 17:26:41 +01:00
asm-generic arch: fix broken BuildID for arm64 and riscv 2022-12-30 17:21:51 +09:00
clocksource Updates for timers, timekeeping and drivers: 2022-12-12 12:52:02 -08:00
crypto
drm Merge drm/drm-fixes into drm-misc-fixes 2023-01-03 08:32:12 +01:00
dt-bindings remoteproc updates for v6.2 2022-12-21 09:37:14 -08:00
keys
kunit kunit: add macro to allow conditionally exposing static symbols to tests 2022-12-12 14:13:48 -07:00
kvm
linux Including fixes from rxrpc. 2023-01-12 18:20:44 -06:00
math-emu
media
memory
misc
net net/sched: sch_taprio: fix possible use-after-free 2023-01-16 13:25:34 +00:00
pcmcia
ras
rdma
rv
scsi Merge branch '6.2/scsi-queue' into 6.2/scsi-fixes 2022-12-30 16:29:34 +00:00
soc Networking changes for 6.2. 2022-12-13 15:47:48 -08:00
sound
target
trace rxrpc: Move client call connection to the I/O thread 2023-01-06 09:43:33 +00:00
uapi block-2023-01-06 2023-01-06 13:12:42 -08:00
ufs
vdso
video fbdev: omapfb: connector-analog-tv: remove support for platform data 2022-12-14 20:01:49 +01:00
xen xen: make remove callback of xen driver void returned 2022-12-15 16:06:10 +01:00