kernel BUG in ext4_mb_load_buddy_gfp

Status: upstream: reported C repro on 2023/05/04 23:52
Reported-by: syzbot+da70412187f83135ac70@syzkaller.appspotmail.com
First crash: 1190d, last: 704d
Cause bisection: failed (error log, bisect log)
  
Fix bisection: failed (error log, bisect log)
  
▶ ▼ Similar bugs (8)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-5-15 kernel BUG in ext4_mb_load_buddy_gfp (2) origin:upstream missing-backport -1 syz, C error done 24 1141d 1188d 0/2 auto-obsoleted due to no activity on 2025/02/16 06:49
android-5-10 kernel BUG in ext4_free_blocks -1 3 1697d 1730d 0/2 auto-closed as invalid on 2022/03/13 09:34
android-6-1 kernel BUG in ext4_mb_load_buddy_gfp -1 syz, C error done 42 1021d 1177d 0/2 auto-obsoleted due to no activity on 2023/12/29 16:31
linux-4.14 kernel BUG in ext4_mb_load_buddy_gfp ext4 -1 syz, C 6 1251d 1925d 0/1 upstream: reported C repro on 2021/04/29 16:39
android-5-10 kernel BUG in ext4_free_blocks (2) ext4 -1 syz, C error 25 1193d 1495d 2/2 fixed on 2023/05/04 14:51
linux-4.19 kernel BUG at fs/ext4/ext4.h:LINE! ext4 -1 syz, C error 13 1272d 2090d 0/1 upstream: reported C repro on 2020/11/15 12:08
android-5-15 kernel BUG in ext4_mb_load_buddy_gfp ext4 -1 syz, C error 9 1231d 1348d 2/2 fixed on 2023/03/28 12:29
android-54 kernel BUG at fs/ext4/ext4.h:LINE! ext4 -1 syz, C 1814 437d 2128d 0/2 upstream: reported C repro on 2020/10/08 13:59
▶ ▼ Last patch testing requests (10)
Created Duration User Patch Repo Result
2026/07/23 14:30 12m retest repro android13-5.10-lts log
2026/05/14 00:18 20m retest repro android13-5.10-lts report log
2026/02/24 14:20 13m retest repro android13-5.10-lts report log
2025/12/16 10:28 9m retest repro android13-5.10-lts report log
2025/10/06 16:45 35m retest repro android13-5.10-lts report log
2025/07/27 17:24 14m retest repro android13-5.10-lts report log
2025/05/15 18:27 19m retest repro android13-5.10-lts report log
2025/03/06 02:01 14m retest repro android13-5.10-lts report log
2024/12/26 00:51 19m retest repro android13-5.10-lts report log
2023/08/24 05:00 19m retest repro android13-5.10-lts report log
▶ ▼ Fix bisection attempts (13)
Created Duration User Patch Repo Result
2024/10/14 23:35 0m bisect fix android13-5.10-lts error job log
2024/09/01 08:15 40m bisect fix android13-5.10-lts OK (0) job log log
2024/08/01 10:50 1h01m bisect fix android13-5.10-lts OK (0) job log log
2024/06/28 08:55 46m bisect fix android13-5.10-lts OK (0) job log log
2024/05/23 12:34 1h17m bisect fix android13-5.10-lts OK (0) job log log
2024/04/19 00:59 59m bisect fix android13-5.10-lts OK (0) job log log
2024/03/16 10:16 42m bisect fix android13-5.10-lts OK (0) job log log
2024/02/12 11:22 45m bisect fix android13-5.10-lts OK (0) job log log
2024/01/11 16:25 44m bisect fix android13-5.10-lts OK (0) job log log
2023/12/12 06:08 55m bisect fix android13-5.10-lts OK (0) job log log
2023/11/11 20:36 1h09m bisect fix android13-5.10-lts OK (0) job log log
2023/10/11 11:16 40m bisect fix android13-5.10-lts OK (0) job log log
2023/09/11 03:20 1h01m bisect fix android13-5.10-lts OK (0) job log log

Sample crash report:
EXT4-fs error (device loop0): ext4_discard_preallocations:4463: comm syz-executor228: Error -117 reading block bitmap for 0
------------[ cut here ]------------
kernel BUG at fs/ext4/ext4.h:3247!
invalid opcode: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 301 Comm: syz-executor228 Not tainted 5.10.177-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
RIP: 0010:ext4_get_group_info fs/ext4/ext4.h:3247 [inline]
RIP: 0010:ext4_mb_load_buddy_gfp+0xf5d/0x1020 fs/ext4/mballoc.c:1174
Code: ff e8 47 3c c8 ff e9 f0 f2 ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 52 f3 ff ff e8 4d 3c c8 ff e9 48 f3 ff ff e8 83 2e 8b ff <0f> 0b e9 62 00 00 00 e8 77 2e 8b ff e9 ef fb ff ff e9 65 00 00 00
RSP: 0018:ffffc90000c36590 EFLAGS: 00010293
RAX: ffffffff81df3e6d RBX: 00000000fffff01a RCX: ffff88810b2ecf00
RDX: 0000000000000000 RSI: 00000000fffff01a RDI: 0000000000000001
RBP: ffffc90000c36610 R08: ffffffff81df2ffc R09: fffff94000852c07
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff88810ac67000 R14: 1ffff1102158c079 R15: ffff88810ac603c8
FS:  00005555571db300(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000562ed30d0278 CR3: 000000010ac35000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 ext4_discard_preallocations+0x79c/0xef0 fs/ext4/mballoc.c:4451
 ext4_truncate+0xa95/0x1220 fs/ext4/inode.c:4362
 ext4_truncate_failed_write fs/ext4/truncate.h:20 [inline]
 ext4_write_begin+0xce0/0x1730 fs/ext4/inode.c:1262
 ext4_da_write_begin+0x49d/0xf60 fs/ext4/inode.c:3031
 generic_perform_write+0x2cd/0x570 mm/filemap.c:3501
 ext4_buffered_write_iter+0x47d/0x610 fs/ext4/file.c:272
 ext4_file_write_iter+0x193/0x1ca0 fs/ext4/file.c:689
 __kernel_write+0x5ab/0x9d0 fs/read_write.c:550
 dump_emit+0x261/0x3a0 fs/coredump.c:849
 dump_user_range+0x71/0x1a0 fs/coredump.c:902
 elf_core_dump+0x33bd/0x3c10 fs/binfmt_elf.c:2287
 do_coredump+0x1eb8/0x2d60 fs/coredump.c:811
 get_signal+0x102c/0x1410 kernel/signal.c:2768
 arch_do_signal_or_restart+0xbd/0x17c0 arch/x86/kernel/signal.c:805
 handle_signal_work kernel/entry/common.c:145 [inline]
 exit_to_user_mode_loop+0x9b/0xd0 kernel/entry/common.c:169
 exit_to_user_mode_prepare kernel/entry/common.c:199 [inline]
 irqentry_exit_to_user_mode+0x55/0x80 kernel/entry/common.c:287
 irqentry_exit+0x12/0x60 kernel/entry/common.c:375
 exc_page_fault+0x33d/0x5b0 arch/x86/mm/fault.c:1521
 asm_exc_page_fault+0x1e/0x30 arch/x86/include/asm/idtentry.h:571
RIP: 0033:0x0
Code: Unable to access opcode bytes at RIP 0xffffffffffffffd6.
RSP: 002b:0000000020000473 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007fa2915b84e8 RCX: 00007fa291540609
RDX: 00007fa2914fdaa3 RSI: 0000000000000058 RDI: 00007fffcf40ee00
RBP: 0000000000000000 R08: 0000000000000755 R09: 00007fffcf40edb0
R10: 00007fffcf40ec50 R11: 0000000000000206 R12: 00007fffcf40eda8
R13: 00007fffcf40ee00 R14: 00007fffcf40edc0 R15: 0000000000000000
Modules linked in:
---[ end trace a3baf27b5dc9ec7e ]---
RIP: 0010:ext4_get_group_info fs/ext4/ext4.h:3247 [inline]
RIP: 0010:ext4_mb_load_buddy_gfp+0xf5d/0x1020 fs/ext4/mballoc.c:1174
Code: ff e8 47 3c c8 ff e9 f0 f2 ff ff 89 f9 80 e1 07 80 c1 03 38 c1 0f 8c 52 f3 ff ff e8 4d 3c c8 ff e9 48 f3 ff ff e8 83 2e 8b ff <0f> 0b e9 62 00 00 00 e8 77 2e 8b ff e9 ef fb ff ff e9 65 00 00 00
RSP: 0018:ffffc90000c36590 EFLAGS: 00010293
RAX: ffffffff81df3e6d RBX: 00000000fffff01a RCX: ffff88810b2ecf00
RDX: 0000000000000000 RSI: 00000000fffff01a RDI: 0000000000000001
RBP: ffffc90000c36610 R08: ffffffff81df2ffc R09: fffff94000852c07
R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000000000001
R13: ffff88810ac67000 R14: 1ffff1102158c079 R15: ffff88810ac603c8
FS:  00005555571db300(0000) GS:ffff8881f7000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005555571e4628 CR3: 000000010ac35000 CR4: 00000000003506b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Crashes (28):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2023/05/06 10:40 android13-5.10-lts 3ad342cf5b2c de870ca5 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/17 15:25 android13-5.10-lts 43c801dc3325 eaac4681 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/17 05:14 android13-5.10-lts 43c801dc3325 11c89444 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/17 04:30 android13-5.10-lts 43c801dc3325 11c89444 .config console log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/04 23:43 android13-5.10-lts 3ad342cf5b2c 518a39a6 .config strace log report syz C [disk image] [vmlinux] [kernel image] [mounted in repro] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/27 20:52 android13-5.10-lts b04c94b9f966 4cd5bb25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/27 09:10 android13-5.10-lts 571f442f6752 4cd5bb25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/26 17:54 android13-5.10-lts 571f442f6752 4cd5bb25 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/26 14:01 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/26 11:20 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/25 06:48 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/25 02:55 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/24 09:15 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/24 06:35 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/24 03:52 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/23 22:59 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/22 19:36 android13-5.10-lts 571f442f6752 79782afc .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/18 19:37 android13-5.10-lts 8a30c9beebe8 f3921d4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/17 21:54 android13-5.10-lts 8a30c9beebe8 f3921d4d .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/06/03 21:21 android13-5.10-lts 43c801dc3325 a4ae4f42 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/29 01:30 android13-5.10-lts 43c801dc3325 cf184559 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/28 21:32 android13-5.10-lts 43c801dc3325 cf184559 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/26 05:02 android13-5.10-lts 43c801dc3325 b40ef614 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/26 00:25 android13-5.10-lts 43c801dc3325 0513b3e6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/24 21:38 android13-5.10-lts 43c801dc3325 4bce1a3e .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/17 03:57 android13-5.10-lts 43c801dc3325 11c89444 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/06 09:41 android13-5.10-lts 3ad342cf5b2c de870ca5 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
2023/05/04 23:21 android13-5.10-lts 3ad342cf5b2c 518a39a6 .config console log report info [disk image] [vmlinux] [kernel image] ci2-android-5-10 kernel BUG in ext4_mb_load_buddy_gfp
* Struck through repros no longer work on HEAD.