syzbot


BUG: unable to handle kernel NULL pointer dereference in udf_getblk

Status: upstream: reported C repro on 2022/10/14 18:29
Reported-by: syzbot+06180202a3562f7bf8cb@syzkaller.appspotmail.com
First crash: 798d, last: 767d
Fix bisection: failed (error log, bisect log)
  

Sample crash report:
loop0: rw=2049, want=2142, limit=2048
Buffer I/O error on dev loop0, logical block 2141, lost async page write
attempt to access beyond end of device
loop0: rw=2049, want=2147, limit=2048
Buffer I/O error on dev loop0, logical block 2146, lost async page write
BUG: unable to handle kernel NULL pointer dereference at 0000000000000000
PGD a49dd067 P4D a49dd067 PUD b3f84067 PMD 0 
Oops: 0002 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 8100 Comm: syz-executor348 Not tainted 4.19.211-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:test_and_set_bit arch/x86/include/asm/bitops.h:209 [inline]
RIP: 0010:test_and_set_bit_lock arch/x86/include/asm/bitops.h:223 [inline]
RIP: 0010:trylock_buffer include/linux/buffer_head.h:367 [inline]
RIP: 0010:lock_buffer include/linux/buffer_head.h:373 [inline]
RIP: 0010:udf_getblk+0x1c1/0x390 fs/udf/inode.c:464
Code: e5 01 89 ee e8 90 f5 f2 fe 40 84 ed 0f 84 00 01 00 00 e8 52 f4 f2 fe 31 d2 be 74 01 00 00 48 c7 c7 a0 80 9a 88 e8 ff e3 d1 fe <f0> 49 0f ba 2c 24 02 40 0f 92 c5 31 ff 89 ee e8 5b f5 f2 fe 40 84
RSP: 0018:ffff88809595f968 EFLAGS: 00010246
RAX: 0000000000000007 RBX: 1ffff11012b2bf2f RCX: 0000000000000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8880b2be8124
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000014bb57f4 R12: 0000000000000000
R13: ffff88808df57bc0 R14: ffff88808df57be8 R15: dffffc0000000000
FS:  0000555556502300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009a145000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 udf_bread+0x85/0x240 fs/udf/inode.c:1206
 udf_add_entry+0xfda/0x2a20 fs/udf/namei.c:509
 udf_mkdir+0x2c7/0x650 fs/udf/namei.c:710
 vfs_mkdir+0x508/0x7a0 fs/namei.c:3819
 do_mkdirat+0x262/0x2d0 fs/namei.c:3842
 do_syscall_64+0xf9/0x620 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fa24bdce649
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffe75c81f38 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa24bdce649
RDX: 0000000000000000 RSI: 0000000020000200 RDI: 0000000000000006
RBP: 00007fa24bd8dc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa24bd8dcb0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
Modules linked in:
CR2: 0000000000000000
---[ end trace 7f943c7746816558 ]---
RIP: 0010:test_and_set_bit arch/x86/include/asm/bitops.h:209 [inline]
RIP: 0010:test_and_set_bit_lock arch/x86/include/asm/bitops.h:223 [inline]
RIP: 0010:trylock_buffer include/linux/buffer_head.h:367 [inline]
RIP: 0010:lock_buffer include/linux/buffer_head.h:373 [inline]
RIP: 0010:udf_getblk+0x1c1/0x390 fs/udf/inode.c:464
Code: e5 01 89 ee e8 90 f5 f2 fe 40 84 ed 0f 84 00 01 00 00 e8 52 f4 f2 fe 31 d2 be 74 01 00 00 48 c7 c7 a0 80 9a 88 e8 ff e3 d1 fe <f0> 49 0f ba 2c 24 02 40 0f 92 c5 31 ff 89 ee e8 5b f5 f2 fe 40 84
RSP: 0018:ffff88809595f968 EFLAGS: 00010246
RAX: 0000000000000007 RBX: 1ffff11012b2bf2f RCX: 0000000000000001
RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8880b2be8124
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000014bb57f4 R12: 0000000000000000
R13: ffff88808df57bc0 R14: ffff88808df57be8 R15: dffffc0000000000
FS:  0000555556502300(0000) GS:ffff8880ba000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000009a145000 CR4: 00000000003406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
   0:	e5 01                	in     $0x1,%eax
   2:	89 ee                	mov    %ebp,%esi
   4:	e8 90 f5 f2 fe       	callq  0xfef2f599
   9:	40 84 ed             	test   %bpl,%bpl
   c:	0f 84 00 01 00 00    	je     0x112
  12:	e8 52 f4 f2 fe       	callq  0xfef2f469
  17:	31 d2                	xor    %edx,%edx
  19:	be 74 01 00 00       	mov    $0x174,%esi
  1e:	48 c7 c7 a0 80 9a 88 	mov    $0xffffffff889a80a0,%rdi
  25:	e8 ff e3 d1 fe       	callq  0xfed1e429
* 2a:	f0 49 0f ba 2c 24 02 	lock btsq $0x2,(%r12) <-- trapping instruction
  31:	40 0f 92 c5          	setb   %bpl
  35:	31 ff                	xor    %edi,%edi
  37:	89 ee                	mov    %ebp,%esi
  39:	e8 5b f5 f2 fe       	callq  0xfef2f599
  3e:	40                   	rex
  3f:	84                   	.byte 0x84

Crashes (5):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2022/11/15 13:05 linux-4.19.y 3f8a27f9e27b 97de9cfc .config console log report syz C [disk image] [vmlinux] [mounted in repro] ci2-linux-4-19 BUG: unable to handle kernel NULL pointer dereference in udf_getblk
2022/10/14 18:56 linux-4.19.y 3f8a27f9e27b 4954e4b2 .config console log report syz [disk image] [vmlinux] [mounted in repro #1] [mounted in repro #2] ci2-linux-4-19 BUG: unable to handle kernel NULL pointer dereference in udf_getblk
2022/11/15 12:46 linux-4.19.y 3f8a27f9e27b 97de9cfc .config console log report info [disk image] [vmlinux] ci2-linux-4-19 BUG: unable to handle kernel NULL pointer dereference in udf_getblk
2022/10/17 05:10 linux-4.19.y 3f8a27f9e27b 67cb024c .config console log report info [disk image] [vmlinux] ci2-linux-4-19 BUG: unable to handle kernel NULL pointer dereference in udf_getblk
2022/10/14 18:28 linux-4.19.y 3f8a27f9e27b 4954e4b2 .config console log report info [disk image] [vmlinux] ci2-linux-4-19 BUG: unable to handle kernel NULL pointer dereference in udf_getblk
* Struck through repros no longer work on HEAD.