general protection fault in bfs_get_block (3)

Status: upstream: reported C repro on 2024/10/30 00:43
Subsystems: bfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+f51a2a34984e4d8888fd@syzkaller.appspotmail.com
First crash: 684d, last: 1d13h
▶ ▼ ✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision
b1db0f71 assessment-security DenialOfService: ✅ Exploitable: ❌ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ✅ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ ❓ general protection fault in bfs_get_block (3) 2026/05/31 06:43 2026/05/31 06:43 2026/05/31 06:48 6b4a8443
39ef46e3 assessment-security 💥 general protection fault in bfs_get_block (3) 2026/05/14 14:28 2026/05/14 14:28 2026/05/14 14:29 6ccb967e
▶ ▼ Discussions (6)
Title Replies (including bot) Last reply
[syzbot] Monthly bfs report (Apr 2026) 0 (1) 2026/04/20 12:38
[syzbot] Monthly bfs report (Jan 2026) 0 (1) 2026/01/12 08:35
[PATCH] bfs: Fix calculation of offset when moving blocks 2 (2) 2025/12/15 07:55
[syzbot] Monthly bfs report (Dec 2025) 0 (1) 2025/12/10 02:19
[syzbot] [bfs?] general protection fault in bfs_get_block (3) 4 (11) 2025/11/19 18:40
[PATCH] bfs: add check for return value of sb_getblk 1 (1) 2024/11/03 14:36
▶ ▼ Similar bugs (3)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in bfs_get_block bfs 2 2 1275d 1311d 0/29 auto-obsoleted due to no activity on 2023/07/13 12:29
linux-6.1 general protection fault in bfs_get_block origin:upstream 8 syz, C error 2 118d 1257d 0/3 upstream: reported C repro on 2023/04/02 00:46
upstream general protection fault in bfs_get_block (2) bfs 2 syz, C error done 2 1001d 1020d 25/29 fixed on 2024/01/30 15:47
▶ ▼ Last patch testing requests (15)
Created Duration User Patch Repo Result
2026/06/09 21:54 30m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci no crash log
2026/03/24 03:41 26m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/03/24 03:28 25m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci error
2026/01/08 04:33 26m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/11/19 18:40 26m zlatistiv@gmail.com patch git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci OK log
2025/09/08 04:00 19m retest repro git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci report log
2025/07/02 02:36 20m retest repro upstream no crash log
2025/06/13 10:18 23m retest repro upstream no crash log
2025/04/23 01:53 14m retest repro upstream report log
2025/04/04 09:51 16m retest repro upstream report log
2025/02/12 01:22 18m retest repro upstream report log
2024/11/03 14:13 18m eadavis@qq.com patch upstream OK log
2024/11/03 06:08 18m eadavis@qq.com patch upstream OK log
2024/11/03 04:37 14m eadavis@qq.com patch upstream report log
2024/11/03 01:37 18m eadavis@qq.com patch upstream report log

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f]
CPU: 0 UID: 0 PID: 8557 Comm: syz.8.471 Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/05/2026
RIP: 0010:bfs_move_block fs/bfs/file.c:43 [inline]
RIP: 0010:bfs_move_blocks fs/bfs/file.c:57 [inline]
RIP: 0010:bfs_get_block+0x583/0xb50 fs/bfs/file.c:126
Code: 89 c5 49 8d 7e 20 48 89 f8 48 c1 e8 03 80 3c 18 00 49 89 df 74 05 e8 0c a6 83 ff 49 8b 6e 20 49 8d 5d 28 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 ee a5 83 ff 4c 89 f7 48 83 c7 28
RSP: 0018:ffffc900041ce618 EFLAGS: 00010216
RAX: 0000000000000005 RBX: 0000000000000028 RCX: ffff8880310eddc0
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88804a721e20
RBP: 0000000000000200 R08: ffffea0001225877 R09: 1ffffd4000244b0e
R10: dffffc0000000000 R11: fffff94000244b0f R12: 0000000000000012
R13: 0000000000000000 R14: ffff88804a721e00 R15: dffffc0000000000
FS:  00007f8f077136c0(0000) GS:ffff888124cd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055652c610008 CR3: 0000000075f2f000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 __block_write_begin_int+0x6c2/0x1900 fs/buffer.c:2030
 block_write_begin+0x8d/0x120 fs/buffer.c:2144
 bfs_write_begin+0x35/0xd0 fs/bfs/file.c:180
 generic_perform_write+0x2d5/0x8f0 mm/filemap.c:4374
 generic_file_write_iter+0xae/0x330 mm/filemap.c:4517
 __kernel_write_iter+0x44a/0x8f0 fs/read_write.c:621
 __kernel_write+0x106/0x170 fs/read_write.c:641
 __dump_emit fs/coredump.c:1215 [inline]
 dump_emit+0x920/0xb00 fs/coredump.c:1253
 writenote+0x1c0/0x2f0 fs/binfmt_elf.c:1431
 write_note_info fs/binfmt_elf.c:1931 [inline]
 elf_core_dump+0x3149/0x3a90 fs/binfmt_elf.c:2093
 coredump_write+0x1290/0x1960 fs/coredump.c:1047
 do_coredump fs/coredump.c:1126 [inline]
 vfs_coredump+0x3764/0x4520 fs/coredump.c:1195
 get_signal+0x1094/0x12c0 kernel/signal.c:3024
 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:101 [inline]
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
 irqentry_exit_to_user_mode_prepare include/linux/irq-entry-common.h:244 [inline]
 irqentry_exit_to_user_mode include/linux/irq-entry-common.h:315 [inline]
 irqentry_exit+0x2ba/0x910 kernel/entry/common.c:165
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:595
RIP: 0033:0x7f8f0679e161
Code: 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 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f8f06a26090 RCX: 00007f8f0679e159
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f8f0683503b R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f8f06a26128 R14: 00007f8f06a26090 R15: 00007ffc20f9ace8
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:bfs_move_block fs/bfs/file.c:43 [inline]
RIP: 0010:bfs_move_blocks fs/bfs/file.c:57 [inline]
RIP: 0010:bfs_get_block+0x583/0xb50 fs/bfs/file.c:126
Code: 89 c5 49 8d 7e 20 48 89 f8 48 c1 e8 03 80 3c 18 00 49 89 df 74 05 e8 0c a6 83 ff 49 8b 6e 20 49 8d 5d 28 48 89 d8 48 c1 e8 03 <42> 80 3c 38 00 74 08 48 89 df e8 ee a5 83 ff 4c 89 f7 48 83 c7 28
RSP: 0018:ffffc900041ce618 EFLAGS: 00010216
RAX: 0000000000000005 RBX: 0000000000000028 RCX: ffff8880310eddc0
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff88804a721e20
RBP: 0000000000000200 R08: ffffea0001225877 R09: 1ffffd4000244b0e
R10: dffffc0000000000 R11: fffff94000244b0f R12: 0000000000000012
R13: 0000000000000000 R14: ffff88804a721e00 R15: dffffc0000000000
FS:  00007f8f077136c0(0000) GS:ffff888124dd6000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b33cfeff8 CR3: 0000000075f2f000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
   0:	89 c5                	mov    %eax,%ebp
   2:	49 8d 7e 20          	lea    0x20(%r14),%rdi
   6:	48 89 f8             	mov    %rdi,%rax
   9:	48 c1 e8 03          	shr    $0x3,%rax
   d:	80 3c 18 00          	cmpb   $0x0,(%rax,%rbx,1)
  11:	49 89 df             	mov    %rbx,%r15
  14:	74 05                	je     0x1b
  16:	e8 0c a6 83 ff       	call   0xff83a627
  1b:	49 8b 6e 20          	mov    0x20(%r14),%rbp
  1f:	49 8d 5d 28          	lea    0x28(%r13),%rbx
  23:	48 89 d8             	mov    %rbx,%rax
  26:	48 c1 e8 03          	shr    $0x3,%rax
* 2a:	42 80 3c 38 00       	cmpb   $0x0,(%rax,%r15,1) <-- trapping instruction
  2f:	74 08                	je     0x39
  31:	48 89 df             	mov    %rbx,%rdi
  34:	e8 ee a5 83 ff       	call   0xff83a627
  39:	4c 89 f7             	mov    %r14,%rdi
  3c:	48 83 c7 28          	add    $0x28,%rdi

Crashes (42):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/09/09 05:55 upstream 893e11787f78 8387c273 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bfs_get_block
2026/05/12 11:41 upstream 50897c955902 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bfs_get_block
2026/05/12 11:26 upstream 50897c955902 d5b1a17d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bfs_get_block
2026/05/04 01:54 upstream f377d0025eb0 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-badwrites-root general protection fault in bfs_get_block
2026/03/09 23:48 upstream 1f318b96cc84 176bead5 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bfs_get_block
2025/11/23 18:00 upstream d13f3ac64efb 4fb8ef37 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in bfs_get_block
2025/11/15 07:23 upstream d4f8cccc6230 f7988ea4 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in bfs_get_block
2025/07/24 09:55 upstream 01a412d06bc5 0c1d6ded .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in bfs_get_block
2026/08/30 03:03 upstream 08dbfad3f504 2f52988a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2026/06/22 00:50 upstream 8cd8cf7a07e5 43bfcdb0 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2026/05/11 13:41 upstream 5d6919055dec 845acb1c .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2026/05/10 11:46 upstream 1bfaee9d3351 29233ece .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2026/04/07 06:00 upstream bfe62a454542 4440e7c2 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/25 04:04 upstream ccd1cdca5cd4 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/20 05:34 upstream dd9b004b7ff3 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/14 09:50 upstream 8f0b4cce4481 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/13 21:23 upstream 9d9c1cfec01c d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/09 15:32 upstream cb015814f8b6 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/09 09:46 upstream a110f942672c d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/08 02:43 upstream 37bb2e7217b0 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/05 01:47 upstream 6dfafbd0299a d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/12/01 10:13 upstream 7d0a66e4bb90 d1b870e1 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/11/01 17:36 upstream ba36dd5ee6fd 2c50b6a9 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/05/17 13:34 upstream 172a9d94339c f41472b0 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/01/29 01:03 upstream 805ba04cb7cc 865ef71e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2025/01/10 09:12 upstream 643e2e259c2b 67d7ec0a .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/12/04 16:56 upstream feffde684ac2 b50eb251 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/11/15 17:57 upstream cfaaa7d010d1 eeafb645 .config console log report syz / log C [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/11/15 17:11 upstream cfaaa7d010d1 eeafb645 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/11/14 17:19 upstream 0a9b9d17f3a7 77f3eeb7 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/11/13 14:55 upstream f1b785f4c787 4dfba277 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/10/29 16:56 upstream e42b1a9a2557 66aeb999 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/10/26 10:29 upstream c71f8fb4dc91 65e8686b .config console log report syz / log [disk image (non-bootable)] [vmlinux] [kernel image] [mounted in repro] ci-snapshot-upstream-root general protection fault in bfs_get_block
2024/10/26 00:37 upstream c71f8fb4dc91 65e8686b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in bfs_get_block
2026/05/26 16:13 linux-next c1ecb239fa34 a3e47276 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in bfs_get_block
2026/05/02 13:22 linux-next b9303e6bff70 a0d91488 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-linux-next-kasan-gce-root general protection fault in bfs_get_block
2026/02/03 22:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 59e4d31a0470 6df4c87a .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
2025/10/12 17:37 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci bf45a62baffc ff1712fe .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
2025/08/24 19:26 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 bf27483f .config console log report syz / log C [disk image] [vmlinux] [kernel image] [mounted in repro] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
2025/08/24 18:46 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
2025/06/16 04:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 39dfc971e42d 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
2025/06/16 04:06 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 39dfc971e42d 5f4b362d .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in bfs_get_block
* Struck through repros no longer work on HEAD.