KASAN: null-ptr-deref Read in drop_buffers

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: aaa11ce2ffc8 Add linux-next specific files for 20220923
git tree: linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=106728ec880000
kernel config: https://syzkaller.appspot.com/x/.config?x=186d1ff305f10294
dashboard link: https://syzkaller.appspot.com/bug?extid=5732a7eeff648d245c7f
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
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.

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/95c7bf83c07e/disk-aaa11ce2.raw.xz
vmlinux: https://storage.googleapis.com/syzbot-assets/b161cd56a7a3/vmlinux-aaa11ce2.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+5732a7...@syzkaller.appspotmail.com

==================================================================
BUG: KASAN: null-ptr-deref in instrument_atomic_read include/linux/instrumented.h:72 [inline]
BUG: KASAN: null-ptr-deref in atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
BUG: KASAN: null-ptr-deref in buffer_busy fs/buffer.c:2787 [inline]
BUG: KASAN: null-ptr-deref in drop_buffers+0x99/0x520 fs/buffer.c:2799
Read of size 4 at addr 0000000000000060 by task syz-executor.1/2809

CPU: 1 PID: 2809 Comm: syz-executor.1 Not tainted 6.0.0-rc6-next-20220923-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/22/2022
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xcd/0x134 lib/dump_stack.c:106
kasan_report+0xbb/0x1f0 mm/kasan/report.c:495
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:72 [inline]
atomic_read include/linux/atomic/atomic-instrumented.h:27 [inline]
buffer_busy fs/buffer.c:2787 [inline]
drop_buffers+0x99/0x520 fs/buffer.c:2799
try_to_free_buffers+0x20c/0x2c0 fs/buffer.c:2829
filemap_release_folio+0x15c/0x1a0 mm/filemap.c:3949
shrink_folio_list+0x1cb4/0x35b0 mm/vmscan.c:1982
shrink_inactive_list mm/vmscan.c:2489 [inline]
shrink_list mm/vmscan.c:2716 [inline]
shrink_lruvec+0xce7/0x26e0 mm/vmscan.c:5888
shrink_node_memcgs mm/vmscan.c:6075 [inline]
shrink_node+0x8d2/0x1f30 mm/vmscan.c:6106
shrink_zones mm/vmscan.c:6344 [inline]
do_try_to_free_pages+0x3b4/0x17a0 mm/vmscan.c:6406
try_to_free_mem_cgroup_pages+0x3a0/0xa70 mm/vmscan.c:6721
reclaim_high.constprop.0+0x182/0x230 mm/memcontrol.c:2404
mem_cgroup_handle_over_high+0x18c/0x510 mm/memcontrol.c:2589
try_charge_memcg+0xe12/0x12f0 mm/memcontrol.c:2827
obj_cgroup_charge_pages mm/memcontrol.c:3110 [inline]
__memcg_kmem_charge_page+0x16a/0x3b0 mm/memcontrol.c:3136
__alloc_pages+0x1ef/0x5a0 mm/page_alloc.c:5563
alloc_pages+0x1a6/0x270 mm/mempolicy.c:2280
vm_area_alloc_pages mm/vmalloc.c:2975 [inline]
__vmalloc_area_node mm/vmalloc.c:3043 [inline]
__vmalloc_node_range+0x954/0x13a0 mm/vmalloc.c:3213
__bpf_map_area_alloc+0xd5/0x150 kernel/bpf/syscall.c:332
bloom_map_alloc+0x322/0x620 kernel/bpf/bloom_filter.c:145
find_and_alloc_map kernel/bpf/syscall.c:131 [inline]
map_create+0x4d3/0x20c0 kernel/bpf/syscall.c:1106
__sys_bpf+0x754/0x4cf0 kernel/bpf/syscall.c:4947
__do_sys_bpf kernel/bpf/syscall.c:5069 [inline]
__se_sys_bpf kernel/bpf/syscall.c:5067 [inline]
__x64_sys_bpf+0x75/0xb0 kernel/bpf/syscall.c:5067
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f6d3d48a5a9
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 b8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f6d3e5c1168 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f6d3d5abf80 RCX: 00007f6d3d48a5a9
RDX: 0000000000000048 RSI: 0000000020000180 RDI: 0000000000000000
RBP: 00007f6d3d4e5580 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fff195ad9ff R14: 00007f6d3e5c1300 R15: 0000000000022000
</TASK>
==================================================================


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[syzbot]

Sending this report upstream.