================================================================== 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.3.1099/10715 CPU: 0 UID: 0 PID: 10715 Comm: syz.3.1099 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Call Trace: 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:200 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/0x4c70 mm/vmscan.c:1511 evict_folios+0x47f2/0x58b0 mm/vmscan.c:4737 try_to_shrink_lruvec+0x8a3/0xb50 mm/vmscan.c:4900 lru_gen_shrink_lruvec mm/vmscan.c:5049 [inline] shrink_lruvec+0x49c/0x2980 mm/vmscan.c:5810 shrink_node_memcgs mm/vmscan.c:6046 [inline] shrink_node+0xa4e/0x3760 mm/vmscan.c:6087 shrink_zones mm/vmscan.c:6331 [inline] do_try_to_free_pages+0x668/0x1960 mm/vmscan.c:6393 try_to_free_mem_cgroup_pages+0x2fa/0x7e0 mm/vmscan.c:6721 try_charge_memcg+0xa40/0x1290 mm/memcontrol.c:2354 try_charge mm/memcontrol.c:2496 [inline] charge_memcg+0x9f/0x180 mm/memcontrol.c:4699 __mem_cgroup_charge+0x25/0x80 mm/memcontrol.c:4716 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_read_folio_gfp+0x8a/0xe0 mm/shmem.c:5992 drm_gem_get_pages+0x223/0xa20 drivers/gpu/drm/drm_gem.c:654 drm_gem_shmem_get_pages_locked+0x201/0x440 drivers/gpu/drm/drm_gem_shmem_helper.c:200 drm_gem_shmem_mmap+0x193/0x460 drivers/gpu/drm/drm_gem_shmem_helper.c:646 drm_gem_mmap_obj+0x187/0x4e0 drivers/gpu/drm/drm_gem.c:1165 drm_gem_mmap+0x384/0x640 drivers/gpu/drm/drm_gem.c:1243 vfs_mmap include/linux/fs.h:2289 [inline] mmap_file mm/internal.h:167 [inline] __mmap_new_file_vma mm/vma.c:2413 [inline] __mmap_new_vma mm/vma.c:2476 [inline] __mmap_region mm/vma.c:2669 [inline] mmap_region+0x18ab/0x20c0 mm/vma.c:2739 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f130018ebe9 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:00007f1300fe5038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f13003b5fa0 RCX: 00007f130018ebe9 RDX: 0000000000000000 RSI: 0000000000001000 RDI: 0000200000ffc000 RBP: 00007f1300211e19 R08: 0000000000000003 R09: 00000001000f0000 R10: 0000000000000011 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f13003b6038 R14: 00007f13003b5fa0 R15: 00007fffbe296e18 ==================================================================