syzbot


general protection fault in detach_extent_buffer_folio (3)

Status: moderation: reported on 2026/04/12 11:37
Subsystems: btrfs
Labels: prio:high
[Documentation on labels]
Reported-by: syzbot+513d3e89d6cd9be3c461@syzkaller.appspotmail.com
First crash: 66d, last: 5d05h
✨ AI Jobs (2)
ID Workflow Result Correct Bug Created Started Finished Revision Error
1d51e9c5-309f-40d5-9bb8-b726b9e72462 assessment-security DenialOfService: ✅ Exploitable: ✅ FilesystemTrigger: ✅ NetworkTrigger: ❌ PeripheralTrigger: ❌ RemoteTrigger: ❌ Unprivileged: ❌ UserNamespace: ❌ VMGuestTrigger: ❌ VMHostTrigger: ❌ general protection fault in detach_extent_buffer_folio (3) 2026/05/31 22:33 2026/05/31 22:33 2026/05/31 23:32 6b4a844333e83556da95d61d7f207e7ef5cd4bc6
8591650d-a36a-476f-a6a8-53e8bb068406 assessment-security 💥 general protection fault in detach_extent_buffer_folio (3) 2026/05/15 07:15 2026/05/15 07:15 2026/05/15 07:16 6ccb967e465e832a7bfd7a116ad00d52a0923a5d failed to run ["make" "KERNELVERSION=syzkaller" "KERNELRELEASE=syzkaller" "LOCALVERSION=-syzkaller" "-j" "32" "ARCH=x86_64" "CC=ccache clang" "LD=ld.lld" "O=/app/workdir/cache/build/6bdb73b993f02e86796a668fa2d9485db4f74142" "-s" "bzImage" "compile_commands.json"]: exit status 2 Root cause: error: unable to open output file 'security/bpf/hooks.o': 'No such file or directory' /app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/security/apparmor/apparmorfs.c:177:28: warning: unused function 'get_loaddata_common_ref' [-Wunused-function] 177 | static struct aa_loaddata *get_loaddata_common_ref(struct aa_common_ref *ref) | ^~~~~~~~~~~~~~~~~~~~~~~ 1 warning generated. /app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/sound/usb/mixer_s1810c.c:633:5: warning: stack frame size (2360) exceeds limit (2048) in 'snd_sc1810_init_mixer' [-Wframe-larger-than] 633 | int snd_sc1810_init_mixer(struct usb_mixer_interface *mixer) | ^ 1 warning generated. fatal error: error in backend: IO failure on output stream: No space left on device PLEASE submit a bug report to https://github.com/llvm/llvm-project/issues/ and include the crash backtrace, preprocessed source, and associated run script. Stack dump: 0. Program arguments: /usr/bin/clang --target=x86_64-linux-gnu -fintegrated-as -Werror=unknown-warning-option -Werror=ignored-optimization-argument -Werror=option-ignored -Werror=unused-command-line-argument -fmacro-prefix-map=/app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/= -std=gnu11 -fshort-wchar -funsigned-char -fno-common -fno-PIE -fno-strict-aliasing -mno-sse -mno-mmx -mno-sse2 -mno-3dnow -mno-avx -mno-sse4a -fcf-protection=branch -fno-jump-tables -m64 -falign-loops=1 -mno-80387 -mno-fp-ret-in-387 -mstack-alignment=8 -mskip-rax-setup -march=x86-64 -mtune=generic -mno-red-zone -mcmodel=kernel -mstack-protector-guard-reg=gs -mstack-protector-guard-symbol=__ref_stack_chk_guard -Wno-sign-compare -fno-asynchronous-unwind-tables -mretpoline-external-thunk -mindirect-branch-cs-prefix -mfunction-return=thunk-extern -fpatchable-function-entry=16,16 -fno-delete-null-pointer-checks -O2 -fstack-protector-strong -fomit-frame-pointer -ftrivial-auto-var-init=zero -fno-stack-clash-protection -falign-functions=16 -fstrict-flex-arrays=3 -fms-extensions -fno-strict-overflow -fno-stack-check -fno-builtin-wcslen -Wall -Wextra -Wundef -Werror=implicit-function-declaration -Werror=implicit-int -Werror=return-type -Werror=strict-prototypes -Wno-format-security -Wno-trigraphs -Wno-frame-address -Wno-address-of-packed-member -Wmissing-declarations -Wmissing-prototypes -Wframe-larger-than=2048 -Wno-gnu -Wno-microsoft-anon-tag -Wno-format-overflow-non-kprintf -Wno-format-truncation-non-kprintf -Wno-default-const-init-unsafe -Wno-type-limits -Wno-pointer-sign -Wcast-function-type -Wno-unterminated-string-initialization -Wimplicit-fallthrough -Werror=date-time -Werror=incompatible-pointer-types -Wenum-conversion -Wunused -Wno-unused-but-set-variable -Wno-unused-const-variable -Wno-format-overflow -Wno-override-init -Wno-pointer-to-enum-cast -Wno-tautological-constant-out-of-range-compare -Wno-unaligned-access -Wno-enum-compare-conditional -Wno-missing-field-initializers -Wno-shift-negative-value -Wno-enum-enum-conversion -Wno-sign-compare -Wno-unused-parameter -g -gdwarf-4 -fsanitize=kernel-address -mllvm -asan-mapping-offset=0xdffffc0000000000 -mllvm -asan-instrumentation-with-call-threshold=10000 -mllvm -asan-stack=1 -mllvm -asan-globals=1 -mllvm -asan-kernel-mem-intrinsic-prefix=1 -fsanitize=array-bounds -fsanitize=shift -fsanitize-coverage=trace-pc -fsanitize-coverage=trace-cmp -fdebug-info-for-profiling -mllvm -enable-fs-discriminator=true -mllvm -improved-fs-discriminator=true -fbasic-block-address-map -nostdinc -I/app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/arch/x86/include -I./arch/x86/include/generated -I/app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/include -I./include -I/app/workdir/cache/src/34f094c99ea22d3ef2bffa00e4ab32cda3e788d9/
Similar bugs (2)
Kernel Title Rank 🛈 Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream general protection fault in detach_extent_buffer_folio (2) btrfs 2 1 185d 181d 0/29 auto-obsoleted due to no activity on 2026/03/21 10:36
upstream general protection fault in detach_extent_buffer_folio btrfs 2 9 722d 738d 26/29 fixed on 2024/07/09 19:14

Sample crash report:
Oops: general protection fault, probably for non-canonical address 0xdffffc0000000028: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000140-0x0000000000000147]
CPU: 0 UID: 0 PID: 5334 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 d0 d2 79 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000fc8ed20 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffffff8bac209e RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8bac209e RDI: 0000000000000028
RBP: ffffffff83f9648a R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006a879a0 R12: 0000000000000000
R13: 0000000000000140 R14: 0000000000000140 R15: 0000000000000001
FS:  00007ff6780986c0(0000) GS:ffff88808c894000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33e2694000 CR3: 000000001f091000 CR4: 0000000000352ef0
Call Trace:
 <TASK>
 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:573
 kasan_check_byte include/linux/kasan.h:402 [inline]
 lock_acquire+0x84/0x350 kernel/locking/lockdep.c:5842
 __raw_spin_lock include/linux/spinlock_api_smp.h:158 [inline]
 _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:158
 spin_lock include/linux/spinlock.h:342 [inline]
 detach_extent_buffer_folio+0xda/0x910 fs/btrfs/extent_io.c:2911
 btrfs_release_extent_buffer_folios+0x68/0x430 fs/btrfs/extent_io.c:2971
 release_extent_buffer+0x16b/0x240 fs/btrfs/extent_io.c:3679
 btrfs_force_cow_block+0x1094/0x2450 fs/btrfs/ctree.c:592
 btrfs_cow_block+0x3c4/0xa90 fs/btrfs/ctree.c:699
 btrfs_search_slot+0xd13/0x2d20 fs/btrfs/ctree.c:2112
 btrfs_truncate_inode_items+0x49c/0x23c0 fs/btrfs/inode-item.c:498
 btrfs_truncate fs/btrfs/inode.c:7933 [inline]
 btrfs_setsize fs/btrfs/inode.c:5459 [inline]
 btrfs_setattr+0xb7b/0x12a0 fs/btrfs/inode.c:5494
 notify_change+0xc1a/0xf40 fs/attr.c:556
 do_truncate+0x1c2/0x250 fs/open.c:68
 handle_truncate fs/namei.c:4307 [inline]
 do_open fs/namei.c:4703 [inline]
 path_openat+0x2f89/0x3860 fs/namei.c:4858
 do_file_open+0x23e/0x4a0 fs/namei.c:4887
 do_sys_openat2+0x113/0x200 fs/open.c:1364
 do_sys_open fs/open.c:1370 [inline]
 __do_sys_creat fs/open.c:1448 [inline]
 __se_sys_creat fs/open.c:1442 [inline]
 __x64_sys_creat+0x8f/0xc0 fs/open.c:1442
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff67719ce59
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:00007ff678097fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 00007ff677416090 RCX: 00007ff67719ce59
RDX: 0000000000000000 RSI: 0000000000000020 RDI: 0000200000000040
RBP: 00007ff677232d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff677416128 R14: 00007ff677416090 R15: 00007ffdac3d4958
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:210
Code: 79 ff ff ff 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 40 d6 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 e9 d0 d2 79 09 cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc9000fc8ed20 EFLAGS: 00010206
RAX: dffffc0000000000 RBX: ffffffff8bac209e RCX: 0000000080000002
RDX: 0000000000000000 RSI: ffffffff8bac209e RDI: 0000000000000028
RBP: ffffffff83f9648a R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: ffffed1006a879a0 R12: 0000000000000000
R13: 0000000000000140 R14: 0000000000000140 R15: 0000000000000001
FS:  00007ff6780986c0(0000) GS:ffff88808c894000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f33e2694000 CR3: 000000001f091000 CR4: 0000000000352ef0
----------------
Code disassembly (best guess), 4 bytes skipped:
   0:	0f 1f 40 00          	nopl   0x0(%rax)
   4:	90                   	nop
   5:	90                   	nop
   6:	90                   	nop
   7:	90                   	nop
   8:	90                   	nop
   9:	90                   	nop
   a:	90                   	nop
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	0f 1f 40 d6          	nopl   -0x2a(%rax)
  18:	48 c1 ef 03          	shr    $0x3,%rdi
  1c:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  23:	fc ff df
* 26:	0f b6 04 07          	movzbl (%rdi,%rax,1),%eax <-- trapping instruction
  2a:	3c 08                	cmp    $0x8,%al
  2c:	0f 92 c0             	setb   %al
  2f:	e9 d0 d2 79 09       	jmp    0x979d304
  34:	cc                   	int3
  35:	66                   	data16
  36:	66                   	data16
  37:	66                   	data16
  38:	66                   	data16
  39:	66                   	data16
  3a:	66                   	data16
  3b:	2e                   	cs

Crashes (3):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2026/06/09 05:44 upstream 2d3090a8aeb5 656e94c6 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in detach_extent_buffer_folio
2026/04/13 05:09 upstream 028ef9c96e96 38c8e246 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in detach_extent_buffer_folio
2026/04/08 11:28 upstream 3036cd0d3328 2c961e87 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in detach_extent_buffer_folio
* Struck through repros no longer work on HEAD.