==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:68 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
BUG: KASAN: null-ptr-deref in buffer_busy fs/buffer.c:2886 [inline]
BUG: KASAN: null-ptr-deref in drop_buffers.constprop.0+0x89/0x340 fs/buffer.c:2898
Read of size 4 at addr 0000000000000060 by task syz.8.5851/28207
CPU: 1 UID: 0 PID: 28207 Comm: syz.8.5851 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
__dump_stack lib/dump_stack.c:94 [inline]
dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120
kasan_report+0xe0/0x110 mm/kasan/report.c:595
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x100/0x1b0 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:68 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline]
buffer_busy fs/buffer.c:2886 [inline]
drop_buffers.constprop.0+0x89/0x340 fs/buffer.c:2898
try_to_free_buffers+0x21c/0x2d0 fs/buffer.c:2952
filemap_release_folio+0x219/0x280 mm/filemap.c:4356
shrink_folio_list+0x28a9/0x4880 mm/vmscan.c:1518
evict_folios+0x79c/0x1b30 mm/vmscan.c:4744
try_to_shrink_lruvec+0x585/0x9b0 mm/vmscan.c:4907
shrink_one+0x3e3/0x7a0 mm/vmscan.c:4952
shrink_many mm/vmscan.c:5015 [inline]
lru_gen_shrink_node mm/vmscan.c:5093 [inline]
shrink_node+0x26b5/0x3d50 mm/vmscan.c:6078
shrink_zones mm/vmscan.c:6336 [inline]
do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6398
try_to_free_pages+0x2a1/0x690 mm/vmscan.c:6644
__perform_reclaim mm/page_alloc.c:4310 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:4332 [inline]
__alloc_pages_slowpath mm/page_alloc.c:4781 [inline]
__alloc_frozen_pages_noprof+0x9fc/0x23f0 mm/page_alloc.c:5161
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_pages_noprof mm/mempolicy.c:2507 [inline]
folio_alloc_noprof+0x20/0x2d0 mm/mempolicy.c:2517
filemap_alloc_folio_noprof+0x3a1/0x470 mm/filemap.c:1007
__filemap_get_folio+0x4a8/0xc30 mm/filemap.c:1981
__iomap_get_folio fs/iomap/buffered-io.c:763 [inline]
iomap_write_begin+0x8a6/0x18a0 fs/iomap/buffered-io.c:828
iomap_write_iter fs/iomap/buffered-io.c:985 [inline]
iomap_file_buffered_write+0x48e/0xac0 fs/iomap/buffered-io.c:1066
xfs_file_buffered_write+0x1a2/0x8f0 fs/xfs/xfs_file.c:981
xfs_file_write_iter+0x47f/0xc20 fs/xfs/xfs_file.c:1133
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f73d518ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f73d6037038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f73d53b5fa0 RCX: 00007f73d518ebe9
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f73d5211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73d53b6038 R14: 00007f73d53b5fa0 R15: 00007ffee258e4a8
==================================================================
Oops: general protection fault, probably for non-canonical address 0xdffffc000000000c: 0000 [#1] SMP KASAN NOPTI
KASAN: null-ptr-deref in range [0x0000000000000060-0x0000000000000067]
CPU: 1 UID: 0 PID: 28207 Comm: syz.8.5851 Tainted: G B syzkaller #0 PREEMPT(full)
Tainted: [B]=BAD_PAGE
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:buffer_busy fs/buffer.c:2886 [inline]
RIP: 0010:drop_buffers.constprop.0+0x90/0x340 fs/buffer.c:2898
Code: 4d 8b 76 08 4c 39 f3 0f 84 84 00 00 00 e8 38 ae 74 ff 4d 8d 66 60 be 04 00 00 00 4c 89 e7 e8 97 16 da ff 4c 89 e0 48 c1 e8 03 <0f> b6 0c 28 4c 89 e0 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 2d
RSP: 0018:ffffc9000b2c6780 EFLAGS: 00010216
RAX: 000000000000000c RBX: ffff88805d707d90 RCX: ffffc90022e83000
RDX: 0000000000080000 RSI: ffffffff8220c907 RDI: 0000000000000007
RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: 0000000000000060
R13: ffffea00016b1c00 R14: 0000000000000000 R15: ffffea00016b1c28
FS: 00007f73d60376c0(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5165b5d000 CR3: 000000003b371000 CR4: 0000000000350ef0
Call Trace:
try_to_free_buffers+0x21c/0x2d0 fs/buffer.c:2952
filemap_release_folio+0x219/0x280 mm/filemap.c:4356
shrink_folio_list+0x28a9/0x4880 mm/vmscan.c:1518
evict_folios+0x79c/0x1b30 mm/vmscan.c:4744
try_to_shrink_lruvec+0x585/0x9b0 mm/vmscan.c:4907
shrink_one+0x3e3/0x7a0 mm/vmscan.c:4952
shrink_many mm/vmscan.c:5015 [inline]
lru_gen_shrink_node mm/vmscan.c:5093 [inline]
shrink_node+0x26b5/0x3d50 mm/vmscan.c:6078
shrink_zones mm/vmscan.c:6336 [inline]
do_try_to_free_pages+0x362/0x1920 mm/vmscan.c:6398
try_to_free_pages+0x2a1/0x690 mm/vmscan.c:6644
__perform_reclaim mm/page_alloc.c:4310 [inline]
__alloc_pages_direct_reclaim mm/page_alloc.c:4332 [inline]
__alloc_pages_slowpath mm/page_alloc.c:4781 [inline]
__alloc_frozen_pages_noprof+0x9fc/0x23f0 mm/page_alloc.c:5161
alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
alloc_pages_noprof mm/mempolicy.c:2507 [inline]
folio_alloc_noprof+0x20/0x2d0 mm/mempolicy.c:2517
filemap_alloc_folio_noprof+0x3a1/0x470 mm/filemap.c:1007
__filemap_get_folio+0x4a8/0xc30 mm/filemap.c:1981
__iomap_get_folio fs/iomap/buffered-io.c:763 [inline]
iomap_write_begin+0x8a6/0x18a0 fs/iomap/buffered-io.c:828
iomap_write_iter fs/iomap/buffered-io.c:985 [inline]
iomap_file_buffered_write+0x48e/0xac0 fs/iomap/buffered-io.c:1066
xfs_file_buffered_write+0x1a2/0x8f0 fs/xfs/xfs_file.c:981
xfs_file_write_iter+0x47f/0xc20 fs/xfs/xfs_file.c:1133
new_sync_write fs/read_write.c:593 [inline]
vfs_write+0x7d3/0x11d0 fs/read_write.c:686
ksys_write+0x12a/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f73d518ebe9
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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f73d6037038 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00007f73d53b5fa0 RCX: 00007f73d518ebe9
RDX: 000000000208e24b RSI: 0000200000000000 RDI: 0000000000000007
RBP: 00007f73d5211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f73d53b6038 R14: 00007f73d53b5fa0 R15: 00007ffee258e4a8
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:33 [inline]
RIP: 0010:buffer_busy fs/buffer.c:2886 [inline]
RIP: 0010:drop_buffers.constprop.0+0x90/0x340 fs/buffer.c:2898
Code: 4d 8b 76 08 4c 39 f3 0f 84 84 00 00 00 e8 38 ae 74 ff 4d 8d 66 60 be 04 00 00 00 4c 89 e7 e8 97 16 da ff 4c 89 e0 48 c1 e8 03 <0f> b6 0c 28 4c 89 e0 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 2d
RSP: 0018:ffffc9000b2c6780 EFLAGS: 00010216
RAX: 000000000000000c RBX: ffff88805d707d90 RCX: ffffc90022e83000
RDX: 0000000000080000 RSI: ffffffff8220c907 RDI: 0000000000000007
RBP: dffffc0000000000 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 3d3d3d3d3d3d3d3d R12: 0000000000000060
R13: ffffea00016b1c00 R14: 0000000000000000 R15: ffffea00016b1c28
FS: 00007f73d60376c0(0000) GS:ffff8881247bd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f5165b5d000 CR3: 000000003b371000 CR4: 0000000000350ef0
----------------
Code disassembly (best guess):
0: 4d 8b 76 08 mov 0x8(%r14),%r14
4: 4c 39 f3 cmp %r14,%rbx
7: 0f 84 84 00 00 00 je 0x91
d: e8 38 ae 74 ff call 0xff74ae4a
12: 4d 8d 66 60 lea 0x60(%r14),%r12
16: be 04 00 00 00 mov $0x4,%esi
1b: 4c 89 e7 mov %r12,%rdi
1e: e8 97 16 da ff call 0xffda16ba
23: 4c 89 e0 mov %r12,%rax
26: 48 c1 e8 03 shr $0x3,%rax
* 2a: 0f b6 0c 28 movzbl (%rax,%rbp,1),%ecx <-- trapping instruction
2e: 4c 89 e0 mov %r12,%rax
31: 83 e0 07 and $0x7,%eax
34: 83 c0 03 add $0x3,%eax
37: 38 c8 cmp %cl,%al
39: 7c 08 jl 0x43
3b: 84 c9 test %cl,%cl
3d: 0f .byte 0xf
3e: 85 .byte 0x85
3f: 2d .byte 0x2d