loop1: detected capacity change from 0 to 16
erofs: (device loop1): mounted with root inode @ nid 36.
attempt to access beyond end of device
loop1: rw=0, want=34359738368, limit=16
attempt to access beyond end of device
loop1: rw=0, want=34359738368, limit=16
general protection fault, probably for non-canonical address 0xdffffc0000000001: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000008-0x000000000000000f]
CPU: 1 PID: 6393 Comm: syz.1.1974 Tainted: G W syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:_compound_head include/linux/page-flags.h:203 [inline]
RIP: 0010:get_page include/linux/mm.h:1267 [inline]
RIP: 0010:z_erofs_lz4_prepare_dstpages fs/erofs/decompressor.c:108 [inline]
RIP: 0010:z_erofs_lz4_decompress+0x4db/0x1c80 fs/erofs/decompressor.c:277
Code: 24 10 4c 8d 34 c8 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 93 ee 87 ff 4d 8b 2e 4d 8d 75 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 76 ee 87 ff 4d 8b 36 44 89 f6 83
RSP: 0018:ffffc90000c06820 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffffc9000578a000 RSI: 0000000000007582 RDI: 0000000000007583
RBP: ffffc90000c06a80 R08: ffffc90000c069f7 R09: 1ffff92000180d3e
R10: dffffc0000000000 R11: fffff52000180d3f R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000001
FS: 00007f9a6af2f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000001c0 CR3: 0000000140ed8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
<TASK>
z_erofs_decompress+0x79/0xb0 fs/erofs/decompressor.c:360
z_erofs_decompress_pcluster fs/erofs/zdata.c:1113 [inline]
z_erofs_decompress_queue+0x1100/0x19e0 fs/erofs/zdata.c:1191
z_erofs_runqueue+0x1145/0x11f0 fs/erofs/zdata.c:1508
z_erofs_readpage+0x25d/0x4d0 fs/erofs/zdata.c:1604
filemap_read_page+0xd3/0x330 mm/filemap.c:2401
filemap_fault+0x1316/0x1cc0 mm/filemap.c:3263
__do_fault+0x25f/0x2f0 mm/memory.c:4195
do_read_fault mm/memory.c:4568 [inline]
do_fault mm/memory.c:4709 [inline]
handle_pte_fault+0x1bc0/0x2770 mm/memory.c:4923
__handle_mm_fault mm/memory.c:-1 [inline]
do_handle_mm_fault+0x1b3b/0x1e30 mm/memory.c:5345
handle_mm_fault include/linux/mm.h:1847 [inline]
do_user_addr_fault+0x808/0x11c0 arch/x86/mm/fault.c:1416
handle_page_fault arch/x86/mm/fault.c:1507 [inline]
exc_page_fault+0x51/0xb0 arch/x86/mm/fault.c:1560
asm_exc_page_fault+0x27/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0010:do_strncpy_from_user lib/strncpy_from_user.c:41 [inline]
RIP: 0010:strncpy_from_user+0xf3/0x2d0 lib/strncpy_from_user.c:139
Code: bf 07 00 00 00 4c 89 ee e8 7a 6c fb fe 49 83 fd 07 0f 86 97 00 00 00 48 c7 45 c0 f8 ff ff ff 45 31 e4 4c 89 7d d0 48 8b 45 c8 <4a> 8b 1c 20 48 b8 ff fe fe fe fe fe fe fe 4c 8d 34 03 49 89 df 49
RSP: 0018:ffffc90000c07cb8 EFLAGS: 00050246
RAX: 00002000000001c0 RBX: 0000000000000fe0 RCX: ffff88810c7b2780
RDX: 0000000000000002 RSI: 0000000000000fe0 RDI: 0000000000000007
RBP: ffffc90000c07d00 R08: ffffea00043fb407 R09: 1ffffd400087f680
R10: dffffc0000000000 R11: fffff9400087f681 R12: 0000000000000000
R13: 0000000000000fe0 R14: 00002000000011a0 R15: ffff88810fed6620
getname_flags+0xf5/0x510 fs/namei.c:149
getname+0x19/0x20 fs/namei.c:217
do_sys_openat2+0xeb/0x7f0 fs/open.c:1230
do_sys_open fs/open.c:1252 [inline]
__do_sys_open fs/open.c:1260 [inline]
__se_sys_open fs/open.c:1256 [inline]
__x64_sys_open+0x11c/0x140 fs/open.c:1256
x64_sys_call+0x3fc/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:3
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f9a6c4f6e59
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:00007f9a6af2f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000002
RAX: ffffffffffffffda RBX: 00007f9a6c77f090 RCX: 00007f9a6c4f6e59
RDX: 0000000000000020 RSI: 000000000014927e RDI: 00002000000001c0
RBP: 00007f9a6c58ce6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f9a6c77f128 R14: 00007f9a6c77f090 R15: 00007ffdcf7ae978
</TASK>
Modules linked in:
---[ end trace e18c519259974293 ]---
RIP: 0010:_compound_head include/linux/page-flags.h:203 [inline]
RIP: 0010:get_page include/linux/mm.h:1267 [inline]
RIP: 0010:z_erofs_lz4_prepare_dstpages fs/erofs/decompressor.c:108 [inline]
RIP: 0010:z_erofs_lz4_decompress+0x4db/0x1c80 fs/erofs/decompressor.c:277
Code: 24 10 4c 8d 34 c8 4c 89 f0 48 c1 e8 03 42 80 3c 20 00 74 08 4c 89 f7 e8 93 ee 87 ff 4d 8b 2e 4d 8d 75 08 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 76 ee 87 ff 4d 8b 36 44 89 f6 83
RSP: 0018:ffffc90000c06820 EFLAGS: 00010202
RAX: 0000000000000001 RBX: 0000000000000001 RCX: 0000000000000000
RDX: ffffc9000578a000 RSI: 0000000000007582 RDI: 0000000000007583
RBP: ffffc90000c06a80 R08: ffffc90000c069f7 R09: 1ffff92000180d3e
R10: dffffc0000000000 R11: fffff52000180d3f R12: dffffc0000000000
R13: 0000000000000000 R14: 0000000000000008 R15: 0000000000000001
FS: 00007f9a6af2f6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000001c0 CR3: 0000000140ed8000 CR4: 00000000003506a0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
----------------
Code disassembly (best guess):
0: 24 10 and $0x10,%al
2: 4c 8d 34 c8 lea (%rax,%rcx,8),%r14
6: 4c 89 f0 mov %r14,%rax
9: 48 c1 e8 03 shr $0x3,%rax
d: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1)
12: 74 08 je 0x1c
14: 4c 89 f7 mov %r14,%rdi
17: e8 93 ee 87 ff call 0xff87eeaf
1c: 4d 8b 2e mov (%r14),%r13
1f: 4d 8d 75 08 lea 0x8(%r13),%r14
23: 4c 89 f0 mov %r14,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction
2f: 74 08 je 0x39
31: 4c 89 f7 mov %r14,%rdi
34: e8 76 ee 87 ff call 0xff87eeaf
39: 4d 8b 36 mov (%r14),%r14
3c: 44 89 f6 mov %r14d,%esi
3f: 83 .byte 0x83