==================================================================
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+0x65/0x4f0 fs/buffer.c:2898
Read of size 4 at addr 0000000000000060 by task syz.1.3767/21897

CPU: 0 UID: 0 PID: 21897 Comm: syz.1.3767 Not tainted 6.17.0-rc1-syzkaller-00211-g90d970cade8e #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 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+0x65/0x4f0 fs/buffer.c:2898
 try_to_free_buffers+0x1e1/0x2d0 fs/buffer.c:2952
 shrink_folio_list+0x20ac/0x4cd0 mm/vmscan.c:1518
 evict_folios+0x47f2/0x58b0 mm/vmscan.c:4744
 try_to_shrink_lruvec+0x8a3/0xb50 mm/vmscan.c:4907
 lru_gen_shrink_lruvec mm/vmscan.c:5056 [inline]
 shrink_lruvec+0x49c/0x2980 mm/vmscan.c:5815
 shrink_node_memcgs mm/vmscan.c:6051 [inline]
 shrink_node+0xa4e/0x3760 mm/vmscan.c:6092
 shrink_zones mm/vmscan.c:6336 [inline]
 do_try_to_free_pages+0x668/0x1960 mm/vmscan.c:6398
 try_to_free_mem_cgroup_pages+0x2fa/0x7e0 mm/vmscan.c:6726
 try_charge_memcg+0xa40/0x1290 mm/memcontrol.c:2357
 try_charge mm/memcontrol.c:2499 [inline]
 charge_memcg+0x9f/0x180 mm/memcontrol.c:4702
 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:4719
 mem_cgroup_charge include/linux/memcontrol.h:654 [inline]
 shmem_alloc_and_add_folio+0x7c1/0xf60 mm/shmem.c:1957
 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597
 shmem_get_folio mm/shmem.c:2703 [inline]
 shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175
 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528
 __kernel_write_iter+0x428/0x910 fs/read_write.c:619
 dump_emit_page fs/coredump.c:1296 [inline]
 dump_user_range+0x8a0/0xc90 fs/coredump.c:1370
 elf_core_dump+0x337b/0x3990 fs/binfmt_elf.c:2085
 coredump_write+0x1169/0x1900 fs/coredump.c:1049
 vfs_coredump+0x1a4b/0x2ab0 fs/coredump.c:1168
 get_signal+0x1109/0x1340 kernel/signal.c:3019
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:73
 exc_page_fault+0x9f/0xf0 arch/x86/mm/fault.c:1535
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 002b:00002000000002e8 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f2c27fb6090 RCX: 00007f2c27d8ebe9
RDX: 0000200000000080 RSI: 00002000000002e0 RDI: 0000000080000000
RBP: 00007f2c27e11e19 R08: 0000200000000100 R09: 0000200000000100
R10: 00002000000000c0 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f2c27fb6128 R14: 00007f2c27fb6090 R15: 00007fffbb9b8d48
 </TASK>
==================================================================