syzbot


general protection fault in xa_destroy

Status: upstream: reported on 2025/08/24 23:26
Subsystems: ext4
[Documentation on labels]
Reported-by: syzbot+1713b1aa266195b916c2@syzkaller.appspotmail.com
Fix commit: 3c3fac6bc0a9 ext4: fix potential null deref in ext4_mb_init()
Patched on: [ci-qemu-gce-upstream-auto ci-qemu-upstream ci-qemu-upstream-386 ci-qemu2-arm32 ci-qemu2-arm64 ci-qemu2-arm64-compat ci-qemu2-arm64-mte ci-qemu2-riscv64 ci-snapshot-upstream-root ci-upstream-bpf-kasan-gce ci-upstream-bpf-next-kasan-gce ci-upstream-gce-leak ci-upstream-kasan-badwrites-root ci-upstream-kasan-gce ci-upstream-kasan-gce-386 ci-upstream-kasan-gce-root ci-upstream-kasan-gce-selinux-root ci-upstream-kasan-gce-smack-root ci-upstream-kmsan-gce-386-root ci-upstream-kmsan-gce-root ci-upstream-linux-next-kasan-gce-root ci-upstream-net-kasan-gce ci-upstream-net-this-kasan-gce ci-upstream-rust-kasan-gce ci2-upstream-fs ci2-upstream-kcsan-gce ci2-upstream-usb], missing on: [ci-qemu-native-arm64-kvm ci-upstream-gce-arm64]
First crash: 74d, last: 15d
Discussions (2)
Title Replies (including bot) Last reply
[PATCH] ext4: fix potential null deref in ext4_mb_init() 5 (5) 2025/09/26 21:47
[syzbot] [ext4?] general protection fault in xa_destroy 1 (2) 2025/08/25 01:28

Sample crash report:
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff9858ade68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff9858adef0 RCX: 00007ff98765038a
RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007ff9858adeb0
RBP: 0000200000000240 R08: 00007ff9858adef0 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000246 R12: 0000200000000280
R13: 00007ff9858adeb0 R14: 0000000000000236 R15: 0000200000000000
 </TASK>
EXT4-fs: no memory for groupinfo slab cache
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000b: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x0000000000000058-0x000000000000005f]
CPU: 0 UID: 0 PID: 5980 Comm: syz.1.2 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc900054f76e0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8af90b18 RCX: 161333de72e1a300
RDX: 0000000000000000 RSI: ffffffff8af90b18 RDI: 000000000000000b
RBP: ffffffff8af586e8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900054f7880 R11: fffff52000a9ef14 R12: 0000000000000000
R13: 0000000000000058 R14: 0000000000000058 R15: 0000000000000001
FS:  00007ff9858ae6c0(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e2912a000 CR3: 00000000343a2000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 __kasan_check_byte+0x12/0x40 mm/kasan/common.c:567
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire+0x8d/0x360 kernel/locking/lockdep.c:5842
 rt_spin_lock+0x88/0x2c0 kernel/locking/spinlock_rt.c:56
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 xa_destroy+0x58/0x2e0 lib/xarray.c:2390
 ext4_mb_avg_fragment_size_destroy fs/ext4/mballoc.c:3659 [inline]
 ext4_mb_init+0x1359/0x2870 fs/ext4/mballoc.c:3817
 __ext4_fill_super fs/ext4/super.c:5558 [inline]
 ext4_fill_super+0x526e/0x60b0 fs/ext4/super.c:5728
 get_tree_bdev_flags+0x40e/0x4d0 fs/super.c:1692
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1815
 do_new_mount+0x2a2/0x9e0 fs/namespace.c:3808
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4324
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff98765038a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff9858ade68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007ff9858adef0 RCX: 00007ff98765038a
RDX: 0000200000000240 RSI: 0000200000000280 RDI: 00007ff9858adeb0
RBP: 0000200000000240 R08: 00007ff9858adef0 R09: 0000000000000004
R10: 0000000000000004 R11: 0000000000000246 R12: 0000200000000280
R13: 00007ff9858adeb0 R14: 0000000000000236 R15: 0000200000000000
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:kasan_byte_accessible+0x12/0x30 mm/kasan/generic.c:199
Code: 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 48 c1 ef 03 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 07 3c 08 0f 92 c0 c3 cc cc cc cc cc 66 66 66 66 66 66 2e
RSP: 0018:ffffc900054f76e0 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: ffffffff8af90b18 RCX: 161333de72e1a300
RDX: 0000000000000000 RSI: ffffffff8af90b18 RDI: 000000000000000b
RBP: ffffffff8af586e8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc900054f7880 R11: fffff52000a9ef14 R12: 0000000000000000
R13: 0000000000000058 R14: 0000000000000058 R15: 0000000000000001
FS:  00007ff9858ae6c0(0000) GS:ffff8881268bf000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f3e2912a000 CR3: 00000000343a2000 CR4: 00000000003526f0
----------------
Code disassembly (best guess):
   0:	d8 64 89 02          	fsubs  0x2(%rcx,%rcx,4)
   4:	48 c7 c0 ff ff ff ff 	mov    $0xffffffffffffffff,%rax
   b:	eb a6                	jmp    0xffffffb3
   d:	e8 de 1a 00 00       	call   0x1af0
  12:	66 2e 0f 1f 84 00 00 	cs nopw 0x0(%rax,%rax,1)
  19:	00 00 00
  1c:	0f 1f 40 00          	nopl   0x0(%rax)
  20:	49 89 ca             	mov    %rcx,%r10
  23:	b8 a5 00 00 00       	mov    $0xa5,%eax
  28:	0f 05                	syscall
* 2a:	48 3d 01 f0 ff ff    	cmp    $0xfffffffffffff001,%rax <-- trapping instruction
  30:	73 01                	jae    0x33
  32:	c3                   	ret
  33:	48 c7 c1 a8 ff ff ff 	mov    $0xffffffffffffffa8,%rcx
  3a:	f7 d8                	neg    %eax
  3c:	64 89 01             	mov    %eax,%fs:(%rcx)
  3f:	48                   	rex.W

Crashes (16):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2025/09/08 16:11 upstream 76eeb9b8de98 d291dd2d .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in xa_destroy
2025/08/30 09:06 upstream fb679c832b64 807a3b61 .config console log report info [disk image] [vmlinux] [kernel image] ci2-upstream-fs general protection fault in xa_destroy
2025/08/26 09:35 upstream fab1beda7597 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in xa_destroy
2025/08/24 23:25 upstream c330cb607721 bf27483f .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-kasan-gce-root general protection fault in xa_destroy
2025/09/29 18:03 upstream e5f0a698b34e 86341da6 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/09/24 14:37 upstream cec1e6e5d1ab 0abd0691 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/09/17 04:16 upstream 5aca7966d2a7 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/09/14 03:36 upstream 5cd64d4f9268 e2beed91 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/09/10 16:39 upstream 9dd1835ecda5 fdeaa69b .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/09/01 21:59 upstream b320789d6883 807a3b61 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/25 12:21 upstream 1b237f190eb3 bf27483f .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/19 15:00 upstream be48bcf004f9 523f460e .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/18 08:07 upstream 8d561baae505 dcc075fb .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/18 00:37 upstream 8d561baae505 dcc075fb .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/01 05:52 upstream d6084bb815c4 0c075d67 .config console log report [disk image (non-bootable)] [vmlinux] [kernel image] ci-snapshot-upstream-root general protection fault in xa_destroy
2025/08/29 06:56 git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux.git for-kernelci 8f5ae30d69d7 3e1beec6 .config console log report info [disk image] [vmlinux] [kernel image] ci-upstream-gce-arm64 BUG: unable to handle kernel paging request in xa_destroy
* Struck through repros no longer work on HEAD.