audit: type=1400 audit(2000000321.593:2464): avc: denied { create } for pid=10875 comm="syz-executor5" scontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=unconfined_u:system_r:insmod_t:s0-s0:c0.c1023 tclass=netlink_generic_socket permissive=0 ================================================================== BUG: KASAN: use-after-free in constant_test_bit arch/x86/include/asm/bitops.h:311 [inline] BUG: KASAN: use-after-free in fuse_dev_do_read.isra.11.constprop.15+0x10c7/0x1220 fs/fuse/dev.c:1314 Read of size 8 at addr ffff8801c65e0de0 by task syz-executor4/10895 CPU: 0 PID: 10895 Comm: syz-executor4 Not tainted 4.9.125+ #37 ffff880185187968 ffffffff81af0ae9 ffffea0007197800 ffff8801c65e0de0 0000000000000000 ffff8801c65e0de0 ffff88019e487a80 ffff8801851879a0 ffffffff814e0e1d ffff8801c65e0de0 0000000000000008 0000000000000000 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] print_address_description+0x6c/0x234 mm/kasan/report.c:256 [] kasan_report_error mm/kasan/report.c:355 [inline] [] kasan_report.cold.6+0x242/0x2fe mm/kasan/report.c:412 [] __asan_report_load8_noabort+0x14/0x20 mm/kasan/report.c:433 [] constant_test_bit arch/x86/include/asm/bitops.h:311 [inline] [] fuse_dev_do_read.isra.11.constprop.15+0x10c7/0x1220 fs/fuse/dev.c:1314 [] fuse_dev_read+0x156/0x1f0 fs/fuse/dev.c:1356 [] new_sync_read fs/read_write.c:439 [inline] [] __vfs_read+0x3d4/0x560 fs/read_write.c:451 [] vfs_read+0x124/0x390 fs/read_write.c:472 [] SYSC_read fs/read_write.c:588 [inline] [] SyS_read+0xd9/0x1c0 fs/read_write.c:581 [] do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 [] entry_SYSCALL_64_after_swapgs+0x5d/0xdb Allocated by task 10878: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:609 kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:594 kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:547 slab_post_alloc_hook mm/slab.h:417 [inline] slab_alloc_node mm/slub.c:2715 [inline] slab_alloc mm/slub.c:2723 [inline] kmem_cache_alloc+0xd5/0x2b0 mm/slub.c:2728 __fuse_request_alloc+0x27/0xe0 fs/fuse/dev.c:58 fuse_request_alloc fs/fuse/dev.c:86 [inline] __fuse_get_req+0x19e/0x510 fs/fuse/dev.c:169 fuse_get_req fs/fuse/dev.c:191 [inline] fuse_simple_request+0x28/0x660 fs/fuse/dev.c:546 fuse_do_getattr+0x23a/0xb70 fs/fuse/dir.c:957 fuse_update_attributes+0x1b1/0x210 fs/fuse/dir.c:983 fuse_getattr+0xc7/0x120 fs/fuse/dir.c:1849 vfs_getattr_nosec+0xd7/0x130 fs/stat.c:57 vfs_getattr+0x32/0x50 fs/stat.c:72 vfs_fstatat+0xe1/0x170 fs/stat.c:110 vfs_lstat fs/stat.c:129 [inline] SYSC_newlstat fs/stat.c:283 [inline] SyS_newlstat+0x89/0x100 fs/stat.c:277 do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb Freed by task 10878: save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 save_stack mm/kasan/kasan.c:505 [inline] set_track mm/kasan/kasan.c:517 [inline] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:582 slab_free_hook mm/slub.c:1355 [inline] slab_free_freelist_hook mm/slub.c:1377 [inline] slab_free mm/slub.c:2958 [inline] kmem_cache_free+0xbe/0x310 mm/slub.c:2980 fuse_request_free+0x8b/0xa0 fs/fuse/dev.c:101 fuse_put_request+0x261/0x310 fs/fuse/dev.c:298 fuse_simple_request+0x3db/0x660 fs/fuse/dev.c:568 fuse_do_getattr+0x23a/0xb70 fs/fuse/dir.c:957 fuse_update_attributes+0x1b1/0x210 fs/fuse/dir.c:983 fuse_getattr+0xc7/0x120 fs/fuse/dir.c:1849 vfs_getattr_nosec+0xd7/0x130 fs/stat.c:57 vfs_getattr+0x32/0x50 fs/stat.c:72 vfs_fstatat+0xe1/0x170 fs/stat.c:110 vfs_lstat fs/stat.c:129 [inline] SYSC_newlstat fs/stat.c:283 [inline] SyS_newlstat+0x89/0x100 fs/stat.c:277 do_syscall_64+0x19f/0x480 arch/x86/entry/common.c:282 entry_SYSCALL_64_after_swapgs+0x5d/0xdb The buggy address belongs to the object at ffff8801c65e0db0 which belongs to the cache fuse_request of size 456 The buggy address is located 48 bytes inside of 456-byte region [ffff8801c65e0db0, ffff8801c65e0f78) The buggy address belongs to the page: page:ffffea0007197800 count:1 mapcount:0 mapping: (null) index:0x0 compound_mapcount: 0 flags: 0x4000000000004080(slab|head) page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c65e0c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c65e0d00: fb fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc >ffff8801c65e0d80: fc fc fc fc fc fc fb fb fb fb fb fb fb fb fb fb ^ ffff8801c65e0e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8801c65e0e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================