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Syzkaller reported the following issue:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 2807 at mm/vmalloc.c:3247 __vmalloc_node_range (mm/vmalloc.c:3361)
Modules linked in:
CPU: 0 PID: 2807 Comm: repro Not tainted 6.6.0-rc2+ #12
Hardware name: Generic DT based system
unwind_backtrace from show_stack (arch/arm/kernel/traps.c:258)
show_stack from dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
dump_stack_lvl from __warn (kernel/panic.c:633 kernel/panic.c:680)
__warn from warn_slowpath_fmt (./include/linux/context_tracking.h:153 kernel/panic.c:700)
warn_slowpath_fmt from __vmalloc_node_range (mm/vmalloc.c:3361 (discriminator 3))
__vmalloc_node_range from vmalloc_user (mm/vmalloc.c:3478)
vmalloc_user from xskq_create (net/xdp/xsk_queue.c:40)
xskq_create from xsk_setsockopt (net/xdp/xsk.c:953 net/xdp/xsk.c:1286)
xsk_setsockopt from __sys_setsockopt (net/socket.c:2308)
__sys_setsockopt from ret_fast_syscall (arch/arm/kernel/entry-common.S:68)
xskq_get_ring_size() uses struct_size() macro to safely calculate the
size of struct xsk_queue and q->nentries of desc members. But the
syzkaller repro was able to set q->nentries with the value initially
taken from copy_from_sockptr() high enough to return SIZE_MAX by
struct_size(). The next PAGE_ALIGN(size) is such case will overflow
the size_t value and set it to 0. This will trigger WARN_ON_ONCE in
vmalloc_user() -> __vmalloc_node_range().
The issue is reproducible on 32-bit arm kernel.
Fixes: 9f78bf330a ("xsk: support use vaddr as ring")
Reported-by: syzbot+fae676d3cf469331fc89@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000c84b4705fb31741e@google.com/T/
Reported-by: syzbot+b132693e925cbbd89e26@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000e20df20606ebab4f@google.com/T/
Signed-off-by: Andrew Kanner <andrew.kanner@gmail.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Tested-by: syzbot+fae676d3cf469331fc89@syzkaller.appspotmail.com
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://syzkaller.appspot.com/bug?extid=fae676d3cf469331fc89
Link: https://lore.kernel.org/bpf/20231007075148.1759-1-andrew.kanner@gmail.com
67 lines
1.3 KiB
C
67 lines
1.3 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/* XDP user-space ring structure
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* Copyright(c) 2018 Intel Corporation.
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*/
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#include <linux/log2.h>
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#include <linux/slab.h>
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#include <linux/overflow.h>
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#include <linux/vmalloc.h>
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#include <net/xdp_sock_drv.h>
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#include "xsk_queue.h"
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static size_t xskq_get_ring_size(struct xsk_queue *q, bool umem_queue)
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{
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struct xdp_umem_ring *umem_ring;
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struct xdp_rxtx_ring *rxtx_ring;
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if (umem_queue)
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return struct_size(umem_ring, desc, q->nentries);
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return struct_size(rxtx_ring, desc, q->nentries);
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}
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struct xsk_queue *xskq_create(u32 nentries, bool umem_queue)
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{
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struct xsk_queue *q;
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size_t size;
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q = kzalloc(sizeof(*q), GFP_KERNEL);
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if (!q)
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return NULL;
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q->nentries = nentries;
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q->ring_mask = nentries - 1;
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size = xskq_get_ring_size(q, umem_queue);
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/* size which is overflowing or close to SIZE_MAX will become 0 in
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* PAGE_ALIGN(), checking SIZE_MAX is enough due to the previous
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* is_power_of_2(), the rest will be handled by vmalloc_user()
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*/
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if (unlikely(size == SIZE_MAX)) {
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kfree(q);
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return NULL;
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}
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size = PAGE_ALIGN(size);
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q->ring = vmalloc_user(size);
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if (!q->ring) {
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kfree(q);
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return NULL;
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}
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q->ring_vmalloc_size = size;
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return q;
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}
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void xskq_destroy(struct xsk_queue *q)
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{
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if (!q)
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return;
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vfree(q->ring);
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kfree(q);
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}
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