syzbot


BUG: unable to handle kernel NULL pointer dereference in fuse_copy_one

Status: moderation: reported on 2024/12/01 15:11
Subsystems: fuse
[Documentation on labels]
Reported-by: syzbot+04080429684545aaecf6@syzkaller.appspotmail.com
First crash: 23d, last: 20d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-54 KASAN: use-after-free Read in fuse_copy_one C 1 44d 767d 0/2 upstream: reported C repro on 2022/11/15 07:36
android-5-15 KASAN: use-after-free Read in fuse_copy_one origin:upstream missing-backport C error error 1 237d 766d 0/2 auto-obsoleted due to no activity on 2024/08/08 22:29
android-5-10 KASAN: use-after-free Read in fuse_copy_one C error inconclusive 1 767d 767d 0/2 auto-obsoleted due to no activity on 2023/05/17 19:00

Sample crash report:
BUG: kernel NULL pointer dereference, address: 0000000000000000
#PF: supervisor write access in kernel mode
#PF: error_code(0x0002) - not-present page
PGD 53fd3067 P4D 53fd3067 PUD 468e6067 PMD 0 
Oops: Oops: 0002 [#1] PREEMPT SMP KASAN NOPTI
CPU: 2 UID: 0 PID: 10001 Comm: syz.4.961 Not tainted 6.12.0-syzkaller-11677-g2ba9f676d0a2 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
RIP: 0010:memcpy+0xc/0x20 arch/x86/lib/memcpy_64.S:38
Code: e9 44 fd ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 48 89 f8 48 89 d1 <f3> a4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90
RSP: 0018:ffffc9000e9078b0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffc9000e907c50 RCX: 0000000000000005
RDX: 0000000000000005 RSI: ffff8880538dd550 RDI: 0000000000000000
RBP: 0000000000000005 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000005
R13: 0000000000000000 R14: 0000000000000005 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88802b600000(0063) knlGS:00000000f5106b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000006afc8000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 fuse_copy_do fs/fuse/dev.c:809 [inline]
 fuse_copy_one+0x1cc/0x230 fs/fuse/dev.c:1065
 fuse_copy_args+0x109/0x690 fs/fuse/dev.c:1083
 copy_out_args fs/fuse/dev.c:1966 [inline]
 fuse_dev_do_write+0x1b0a/0x3100 fs/fuse/dev.c:2052
 fuse_dev_write+0x160/0x1f0 fs/fuse/dev.c:2087
 new_sync_write fs/read_write.c:586 [inline]
 vfs_write+0x5ae/0x1150 fs/read_write.c:679
 ksys_write+0x12b/0x250 fs/read_write.c:731
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf741e579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000f5106520 EFLAGS: 00000293 ORIG_RAX: 0000000000000004
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000020000540
RDX: 0000000000000015 RSI: 00000000f7410ff4 RDI: 0000000000000000
RBP: 0000000020008380 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
Modules linked in:
CR2: 0000000000000000
---[ end trace 0000000000000000 ]---
RIP: 0010:memcpy+0xc/0x20 arch/x86/lib/memcpy_64.S:38
Code: e9 44 fd ff ff 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 48 89 f8 48 89 d1 <f3> a4 c3 cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90
RSP: 0018:ffffc9000e9078b0 EFLAGS: 00010293
RAX: 0000000000000000 RBX: ffffc9000e907c50 RCX: 0000000000000005
RDX: 0000000000000005 RSI: ffff8880538dd550 RDI: 0000000000000000
RBP: 0000000000000005 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000005
R13: 0000000000000000 R14: 0000000000000005 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff88802b600000(0063) knlGS:00000000f5106b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000006afc8000 CR4: 0000000000352ef0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e9 44 fd ff ff       	jmp    0xfffffd49
   5:	66 0f 1f 84 00 00 00 	nopw   0x0(%rax,%rax,1)
   c:	00 00
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	f3 0f 1e fa          	endbr64
  22:	66 90                	xchg   %ax,%ax
  24:	48 89 f8             	mov    %rdi,%rax
  27:	48 89 d1             	mov    %rdx,%rcx
* 2a:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi) <-- trapping instruction
  2c:	c3                   	ret
  2d:	cc                   	int3
  2e:	cc                   	int3
  2f:	cc                   	int3
  30:	cc                   	int3
  31:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  38:	00 00 00 00
  3c:	66 90                	xchg   %ax,%ax
  3e:	90                   	nop
  3f:	90                   	nop

Crashes (4):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2024/11/30 16:30 upstream 2ba9f676d0a2 68914665 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 BUG: unable to handle kernel NULL pointer dereference in fuse_copy_one
2024/11/30 16:28 upstream 2ba9f676d0a2 68914665 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 BUG: unable to handle kernel NULL pointer dereference in fuse_copy_one
2024/11/28 11:53 upstream b86545e02e8c 5df23865 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 BUG: unable to handle kernel NULL pointer dereference in fuse_copy_one
2024/11/27 15:00 upstream aaf20f870da0 5df23865 .config console log report info [disk image (non-bootable)] [vmlinux] [kernel image] ci-qemu-upstream-386 BUG: unable to handle kernel NULL pointer dereference in fuse_copy_one
* Struck through repros no longer work on HEAD.