audit: type=1804 audit(1538890925.065:293): pid=12657 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=open_writers comm="syz-executor5" name="/root/syzkaller-testdir522306344/syzkaller.yk2juV/466/bus" dev="sda1" ino=16581 res=1 gfs2: not a GFS2 filesystem gfs2: can't alloc struct gfs2_sbd ================================================================== BUG: KASAN: use-after-free in atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] BUG: KASAN: use-after-free in gfs2_log_flush+0x1ec/0x29b0 fs/gfs2/log.c:779 Read of size 4 at addr ffff880185d453e0 by task syz-executor4/12671 CPU: 0 PID: 12671 Comm: syz-executor4 Not tainted 4.19.0-rc6-next-20181005+ #88 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 audit: type=1804 audit(1538890925.105:294): pid=12657 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor5" name="/root/syzkaller-testdir522306344/syzkaller.yk2juV/466/bus" dev="sda1" ino=16581 res=1 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412 check_memory_region_inline mm/kasan/kasan.c:260 [inline] check_memory_region+0x13e/0x1b0 mm/kasan/kasan.c:267 kasan_check_read+0x11/0x20 mm/kasan/kasan.c:272 atomic_read include/asm-generic/atomic-instrumented.h:21 [inline] gfs2_log_flush+0x1ec/0x29b0 fs/gfs2/log.c:779 gfs2_kill_sb+0x5b/0x1a0 fs/gfs2/ops_fstype.c:1368 deactivate_locked_super+0x97/0x100 fs/super.c:328 gfs2_mount+0x568/0x712 fs/gfs2/ops_fstype.c:1317 legacy_get_tree+0x131/0x460 fs/fs_context.c:718 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1795 do_new_mount fs/namespace.c:2648 [inline] do_mount+0x70c/0x1d90 fs/namespace.c:2974 ksys_mount+0x12d/0x140 fs/namespace.c:3190 __do_sys_mount fs/namespace.c:3204 [inline] __se_sys_mount fs/namespace.c:3201 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3201 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457579 Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f04d5927c78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457579 RDX: 0000000020000300 RSI: 00000000200002c0 RDI: 0000000020000000 RBP: 000000000072bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f04d59286d4 R13: 00000000004c28af R14: 00000000004d3c78 R15: 00000000ffffffff Allocated by task 12671: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x152/0x750 mm/slab.c:3620 kmalloc include/linux/slab.h:546 [inline] kzalloc include/linux/slab.h:741 [inline] init_sbd+0x13f/0xfa0 fs/gfs2/ops_fstype.c:71 fill_super+0xab/0x1a10 fs/gfs2/ops_fstype.c:1041 gfs2_mount+0x5e6/0x712 fs/gfs2/ops_fstype.c:1303 legacy_get_tree+0x131/0x460 fs/fs_context.c:718 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1795 do_new_mount fs/namespace.c:2648 [inline] do_mount+0x70c/0x1d90 fs/namespace.c:2974 ksys_mount+0x12d/0x140 fs/namespace.c:3190 __do_sys_mount fs/namespace.c:3204 [inline] __se_sys_mount fs/namespace.c:3201 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3201 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 12671: save_stack+0x43/0xd0 mm/kasan/kasan.c:448 set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3817 init_sbd+0xe39/0xfa0 fs/gfs2/ops_fstype.c:79 fill_super+0xab/0x1a10 fs/gfs2/ops_fstype.c:1041 gfs2_mount+0x5e6/0x712 fs/gfs2/ops_fstype.c:1303 legacy_get_tree+0x131/0x460 fs/fs_context.c:718 vfs_get_tree+0x1cb/0x5c0 fs/super.c:1795 do_new_mount fs/namespace.c:2648 [inline] do_mount+0x70c/0x1d90 fs/namespace.c:2974 ksys_mount+0x12d/0x140 fs/namespace.c:3190 __do_sys_mount fs/namespace.c:3204 [inline] __se_sys_mount fs/namespace.c:3201 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3201 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff880185d44440 which belongs to the cache kmalloc-8k of size 8192 The buggy address is located 4000 bytes inside of 8192-byte region [ffff880185d44440, ffff880185d46440) The buggy address belongs to the page: page:ffffea0006175100 count:1 mapcount:0 mapping:ffff8801da802080 index:0x0 compound_mapcount: 0 flags: 0x2fffc0000010200(slab|head) raw: 02fffc0000010200 ffffea0005f28f08 ffffea0006e97c08 ffff8801da802080 raw: 0000000000000000 ffff880185d44440 0000000100000001 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff880185d45280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880185d45300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff880185d45380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff880185d45400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff880185d45480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== audit: type=1804 audit(1538890925.125:295): pid=12657 uid=0 auid=4294967295 ses=4294967295 subj==unconfined op=invalid_pcr cause=ToMToU comm="syz-executor5" name="/root/syzkaller-testdir522306344/syzkaller.yk2juV/466/bus" dev="sda1" ino=16581 res=1