KASAN: user-memory-access Read in block_dirty_folio

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: 38d741cb70b3 Merge tag 'drm-fixes-2022-04-29' of git://ano..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=13423d78f00000
kernel config: https://syzkaller.appspot.com/x/.config?x=864dc6814306810
dashboard link: https://syzkaller.appspot.com/bug?extid=af32d919b2cdac25e5eb
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
userspace arch: i386
CC: [linux-...@vger.kernel.org linux-...@vger.kernel.org vi...@zeniv.linux.org.uk]

Unfortunately, I don't have any reproducer for this issue yet.

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+af32d9...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: user-memory-access in instrument_atomic_read include/linux/instrumented.h:71 [inline]
BUG: KASAN: user-memory-access in test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
BUG: KASAN: user-memory-access in set_buffer_dirty include/linux/buffer_head.h:121 [inline]
BUG: KASAN: user-memory-access in block_dirty_folio+0x9c/0x1d0 fs/buffer.c:627
Read of size 8 at addr 0000000000150000 by task syz-executor.2/7218

CPU: 1 PID: 7218 Comm: syz-executor.2 Not tainted 5.18.0-rc4-syzkaller-00192-g38d741cb70b3 #0
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.14.0-2 04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
print_report mm/kasan/report.c:432 [inline]
kasan_report.cold+0x61/0x1c6 mm/kasan/report.c:491
check_region_inline mm/kasan/generic.c:183 [inline]
kasan_check_range+0x13d/0x180 mm/kasan/generic.c:189
instrument_atomic_read include/linux/instrumented.h:71 [inline]
test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
set_buffer_dirty include/linux/buffer_head.h:121 [inline]
block_dirty_folio+0x9c/0x1d0 fs/buffer.c:627
folio_mark_dirty+0xc1/0x140 mm/page-writeback.c:2630
filemap_page_mkwrite+0x50b/0x750 mm/filemap.c:3431
do_page_mkwrite+0x1a7/0x920 mm/memory.c:2885
wp_page_shared mm/memory.c:3208 [inline]
do_wp_page+0x100a/0x2030 mm/memory.c:3325
handle_pte_fault mm/memory.c:4645 [inline]
__handle_mm_fault+0x1dc8/0x4150 mm/memory.c:4763
handle_mm_fault+0x1c8/0x790 mm/memory.c:4861
faultin_page mm/gup.c:878 [inline]
__get_user_pages+0x4f7/0xf10 mm/gup.c:1099
__get_user_pages_locked mm/gup.c:1289 [inline]
__get_user_pages_remote+0x18f/0x840 mm/gup.c:1934
pin_user_pages_remote+0x63/0x90 mm/gup.c:2948
process_vm_rw_single_vec mm/process_vm_access.c:105 [inline]
process_vm_rw_core.constprop.0+0x445/0x990 mm/process_vm_access.c:215
process_vm_rw+0x29c/0x300 mm/process_vm_access.c:283
__do_sys_process_vm_writev mm/process_vm_access.c:303 [inline]
__se_sys_process_vm_writev mm/process_vm_access.c:298 [inline]
__ia32_sys_process_vm_writev+0xdc/0x1b0 mm/process_vm_access.c:298
do_syscall_32_irqs_on arch/x86/entry/common.c:112 [inline]
__do_fast_syscall_32+0x65/0xf0 arch/x86/entry/common.c:178
do_fast_syscall_32+0x2f/0x70 arch/x86/entry/common.c:203
entry_SYSENTER_compat_after_hwframe+0x4d/0x5c
RIP: 0023:0xf7f36549
Code: 03 74 c0 01 10 05 03 74 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 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:00000000f7f105cc EFLAGS: 00000296 ORIG_RAX: 000000000000015c
RAX: ffffffffffffffda RBX: 0000000000000342 RCX: 0000000020c22000
RDX: 0000000000000001 RSI: 0000000020c22fa0 RDI: 0000000000000001
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
</TASK>
==================================================================
----------------
Code disassembly (best guess):
0: 03 74 c0 01 add 0x1(%rax,%rax,8),%esi
4: 10 05 03 74 b8 01 adc %al,0x1b87403(%rip) # 0x1b8740d
a: 10 06 adc %al,(%rsi)
c: 03 74 b4 01 add 0x1(%rsp,%rsi,4),%esi
10: 10 07 adc %al,(%rdi)
12: 03 74 b0 01 add 0x1(%rax,%rsi,4),%esi
16: 10 08 adc %cl,(%rax)
18: 03 74 d8 01 add 0x1(%rax,%rbx,8),%esi
1c: 00 00 add %al,(%rax)
1e: 00 00 add %al,(%rax)
20: 00 51 52 add %dl,0x52(%rcx)
23: 55 push %rbp
24: 89 e5 mov %esp,%ebp
26: 0f 34 sysenter
28: cd 80 int $0x80
* 2a: 5d pop %rbp <-- trapping instruction
2b: 5a pop %rdx
2c: 59 pop %rcx
2d: c3 retq
2e: 90 nop
2f: 90 nop
30: 90 nop
31: 90 nop
32: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi
39: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.