syzbot


BUG: unable to handle kernel paging request in sk_filter_trim_cap

Status: premoderation: reported on 2026/01/22 13:25
Reported-by: syzbot+2cf20a09590f016dc751@syzkaller.appspotmail.com
First crash: 3d12h, last: 3d12h
Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
linux-4.19 KASAN: use-after-free Read in sk_filter_trim_cap 19 1 1418d 1418d 0/1 auto-closed as invalid on 2022/07/07 20:56
linux-6.1 KASAN: use-after-free Read in sk_filter_trim_cap 19 1 555d 555d 0/3 auto-obsoleted due to no activity on 2024/10/27 21:54
upstream KASAN: slab-use-after-free Read in sk_filter_trim_cap bpf net 19 12 259d 508d 0/29 auto-obsoleted due to no activity on 2025/08/19 23:25

Sample crash report:
BUG: unable to handle page fault for address: ffffe6303ef94fc2
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 10003a067 P4D 10003a067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8724 Comm: syz.5.39944 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__bpf_prog_run_save_cb include/linux/filter.h:718 [inline]
RIP: 0010:bpf_prog_run_save_cb include/linux/filter.h:732 [inline]
RIP: 0010:sk_filter_trim_cap+0x67c/0x6f0 net/core/filter.c:152
Code: c5 c0 66 bf 85 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 c3 86 f9 fd 48 8b 44 24 20 49 03 06 49 89 c6 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 a5 86 f9 fd 49 ff 06 e8 0d 9f 82
RSP: 0018:ffffc90000ba7820 EFLAGS: 00010a02
RAX: 1fffea303ef94fc2 RBX: ffff888112486dc0 RCX: ffff88811c35cf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffc90000ba78d0 R08: ffffffff86e78048 R09: ffffffff86e78058
R10: ffffffff86e7805c R11: ffffffff86e78043 R12: 1ffff92000030200
R13: dffffc0000000000 R14: ffff5181f7ca7e10 R15: 000000006c11b03c
FS:  00007ff3accc66c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffe6303ef94fc2 CR3: 00000001236bf000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 sk_filter include/linux/filter.h:862 [inline]
 unix_dgram_sendmsg+0xb1d/0x17e0 net/unix/af_unix.c:1756
 sock_sendmsg_nosec net/socket.c:652 [inline]
 __sock_sendmsg net/socket.c:664 [inline]
 ____sys_sendmsg+0x5b7/0x8f0 net/socket.c:2376
 ___sys_sendmsg+0x236/0x2e0 net/socket.c:2430
 __sys_sendmsg net/socket.c:2459 [inline]
 __do_sys_sendmsg net/socket.c:2468 [inline]
 __se_sys_sendmsg net/socket.c:2466 [inline]
 __x64_sys_sendmsg+0x1f9/0x2c0 net/socket.c:2466
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7ff3ae269cb9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3accc6028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007ff3ae4e4fa0 RCX: 00007ff3ae269cb9
RDX: 0000000000000000 RSI: 0000200000000140 RDI: 0000000000000007
RBP: 00007ff3ae2d7bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3ae4e5038 R14: 00007ff3ae4e4fa0 R15: 00007fff9a8c4ce8
Modules linked in:
CR2: ffffe6303ef94fc2
---[ end trace 212a4ab558ef81c8 ]---
RIP: 0010:__bpf_prog_run_save_cb include/linux/filter.h:718 [inline]
RIP: 0010:bpf_prog_run_save_cb include/linux/filter.h:732 [inline]
RIP: 0010:sk_filter_trim_cap+0x67c/0x6f0 net/core/filter.c:152
Code: c5 c0 66 bf 85 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 f7 e8 c3 86 f9 fd 48 8b 44 24 20 49 03 06 49 89 c6 48 c1 e8 03 <42> 80 3c 28 00 74 08 4c 89 f7 e8 a5 86 f9 fd 49 ff 06 e8 0d 9f 82
RSP: 0018:ffffc90000ba7820 EFLAGS: 00010a02
RAX: 1fffea303ef94fc2 RBX: ffff888112486dc0 RCX: ffff88811c35cf00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000008
RBP: ffffc90000ba78d0 R08: ffffffff86e78048 R09: ffffffff86e78058
R10: ffffffff86e7805c R11: ffffffff86e78043 R12: 1ffff92000030200
R13: dffffc0000000000 R14: ffff5181f7ca7e10 R15: 000000006c11b03c
FS:  00007ff3accc66c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffe6303ef94fc2 CR3: 00000001236bf000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000200000000300
DR3: 0000200000000300 DR6: 00000000ffff0ff0 DR7: 0000000000000600
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	c0 66 bf 85          	shlb   $0x85,-0x41(%rsi)
   4:	4c 89 f0             	mov    %r14,%rax
   7:	48 c1 e8 03          	shr    $0x3,%rax
   b:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1)
  10:	74 08                	je     0x1a
  12:	4c 89 f7             	mov    %r14,%rdi
  15:	e8 c3 86 f9 fd       	call   0xfdf986dd
  1a:	48 8b 44 24 20       	mov    0x20(%rsp),%rax
  1f:	49 03 06             	add    (%r14),%rax
  22:	49 89 c6             	mov    %rax,%r14
  25:	48 c1 e8 03          	shr    $0x3,%rax
* 29:	42 80 3c 28 00       	cmpb   $0x0,(%rax,%r13,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 a5 86 f9 fd       	call   0xfdf986dd
  38:	49 ff 06             	incq   (%r14)
  3b:	e8                   	.byte 0xe8
  3c:	0d                   	.byte 0xd
  3d:	9f                   	lahf
  3e:	82                   	.byte 0x82

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/01/22 13:25 android13-5.10-lts 5601baec60aa a16aed1d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10-perf BUG: unable to handle kernel paging request in sk_filter_trim_cap
* Struck through repros no longer work on HEAD.