Re: [syzbot] [bluetooth?] KASAN: slab-use-after-free Read in skb_queue_purge_reason (2)

syzbot
2025-02-04T14:48:27Z

syzbot has found a reproducer for the following issue on:

HEAD commit: 40b8e93e17bf Add linux-next specific files for 20250204
git tree: linux-next
console+strace: https://syzkaller.appspot.com/x/log.txt?x=113d5d18580000
kernel config: https://syzkaller.appspot.com/x/.config?x=ec880188a87c6aad
dashboard link: https://syzkaller.appspot.com/bug?extid=683f8cb11b94b1824c77
compiler: Debian clang version 15.0.6, GNU ld (GNU Binutils for Debian) 2.40
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=10b7eeb0580000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12f74f64580000

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/ccdfef06f59f/disk-40b8e93e.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b339eaf8dcfd/vmlinux-40b8e93e.xz
kernel image: https://storage.googleapis.com/syzbot-assets/ae1a0f1c3c80/bzImage-40b8e93e.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+683f8cb11b94b1824c77@syzkaller.appspotmail.com

Oops: general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 0 UID: 0 PID: 5833 Comm: syz-executor346 Not tainted 6.14.0-rc1-next-20250204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024
RIP: 0010:skb_queue_empty_lockless include/linux/skbuff.h:1887 [inline]
RIP: 0010:skb_queue_purge_reason+0xaa/0x500 net/core/skbuff.c:3936
Code: 89 44 24 78 42 c6 44 30 13 f3 e8 81 76 05 f8 48 8d bc 24 b0 00 00 00 ba 48 00 00 00 31 f6 e8 0d f2 6b f8 4d 89 ef 49 c1 ef 03 <43> 80 3c 37 00 74 08 4c 89 ef e8 27 ef 6b f8 49 8b 45 00 4c 39 e8
RSP: 0018:ffffc90003d17880 EFLAGS: 00010202
RAX: ffffc90003d17930 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90003d17978
RBP: ffffc90003d179f0 R08: ffffc90003d17977 R09: 0000000000000000
R10: ffffc90003d17930 R11: fffff520007a2f2f R12: dffffc0000000000
R13: 0000000000000008 R14: dffffc0000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055867393d608 CR3: 000000000e738000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
skb_queue_purge include/linux/skbuff.h:3364 [inline]
mrvl_close+0x8e/0x120 drivers/bluetooth/hci_mrvl.c:100
hci_uart_tty_close+0x205/0x290 drivers/bluetooth/hci_ldisc.c:557
tty_ldisc_kill+0xa3/0x1a0 drivers/tty/tty_ldisc.c:613
tty_ldisc_release+0x1a1/0x200 drivers/tty/tty_ldisc.c:781
tty_release_struct+0x2b/0xe0 drivers/tty/tty_io.c:1690
tty_release+0xd06/0x12c0 drivers/tty/tty_io.c:1861
__fput+0x3e9/0x9f0 fs/file_table.c:448
task_work_run+0x24f/0x310 kernel/task_work.c:227
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0xa2a/0x28e0 kernel/exit.c:938
do_group_exit+0x207/0x2c0 kernel/exit.c:1087
__do_sys_exit_group kernel/exit.c:1098 [inline]
__se_sys_exit_group kernel/exit.c:1096 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1096
x64_sys_call+0x26a8/0x26b0 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f794f6cfc79
Code: Unable to access opcode bytes at 0x7f794f6cfc4f.
RSP: 002b:00007fff04322488 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f794f6cfc79
RDX: 000000000000003c RSI: 00000000000000e7 RDI: 0000000000000000
RBP: 00007f794f74a270 R08: ffffffffffffffb8 R09: 00007fff043226a8
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f794f74a270
R13: 0000000000000000 R14: 00007f794f74acc0 R15: 00007f794f6a1a60
</TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:skb_queue_empty_lockless include/linux/skbuff.h:1887 [inline]
RIP: 0010:skb_queue_purge_reason+0xaa/0x500 net/core/skbuff.c:3936
Code: 89 44 24 78 42 c6 44 30 13 f3 e8 81 76 05 f8 48 8d bc 24 b0 00 00 00 ba 48 00 00 00 31 f6 e8 0d f2 6b f8 4d 89 ef 49 c1 ef 03 <43> 80 3c 37 00 74 08 4c 89 ef e8 27 ef 6b f8 49 8b 45 00 4c 39 e8
RSP: 0018:ffffc90003d17880 EFLAGS: 00010202
RAX: ffffc90003d17930 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffc90003d17978
RBP: ffffc90003d179f0 R08: ffffc90003d17977 R09: 0000000000000000
R10: ffffc90003d17930 R11: fffff520007a2f2f R12: dffffc0000000000
R13: 0000000000000008 R14: dffffc0000000000 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055867393d608 CR3: 000000000e738000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 89 44 24 78 mov %eax,0x78(%rsp)
4: 42 c6 44 30 13 f3 movb $0xf3,0x13(%rax,%r14,1)
a: e8 81 76 05 f8 call 0xf8057690
f: 48 8d bc 24 b0 00 00 lea 0xb0(%rsp),%rdi
16: 00
17: ba 48 00 00 00 mov $0x48,%edx
1c: 31 f6 xor %esi,%esi
1e: e8 0d f2 6b f8 call 0xf86bf230
23: 4d 89 ef mov %r13,%r15
26: 49 c1 ef 03 shr $0x3,%r15
* 2a: 43 80 3c 37 00 cmpb $0x0,(%r15,%r14,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 ef mov %r13,%rdi
34: e8 27 ef 6b f8 call 0xf86bef60
39: 49 8b 45 00 mov 0x0(%r13),%rax
3d: 4c 39 e8 cmp %r13,%rax

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#syz test: git://repo/address.git branch-or-commit-hash
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