RDX: 0000000020000380 RSI: 00000000200002c0 RDI: 0000000000000000 RBP: 000000000072bf00 R08: 0000000020000740 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f941ce206d4 R13: 00000000004c28a1 R14: 00000000004d3c90 R15: 0000000000000005 ================================================================== BUG: KASAN: double-free or invalid-free in fscache_free_cookie+0x230/0x280 fs/fscache/cookie.c:67 CPU: 0 PID: 27189 Comm: syz-executor2 Not tainted 4.19.0-rc7+ #62 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1c4/0x2b4 lib/dump_stack.c:113 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256 kasan_report_invalid_free+0x64/0xa0 mm/kasan/report.c:336 __kasan_slab_free+0x13a/0x150 mm/kasan/kasan.c:501 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528 __cache_free mm/slab.c:3498 [inline] kfree+0xcf/0x230 mm/slab.c:3813 fscache_free_cookie+0x230/0x280 fs/fscache/cookie.c:67 fscache_alloc_cookie+0x74c/0x880 fs/fscache/cookie.c:202 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] v9fs_cache_session_get_cookie+0xc4/0x270 fs/9p/cache.c:73 v9fs_session_init+0xffe/0x1a70 fs/9p/v9fs.c:464 v9fs_mount+0x7d/0x8f0 fs/9p/vfs_super.c:135 mount_fs+0xae/0x31d fs/super.c:1261 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2457 [inline] do_mount+0x581/0x31f0 fs/namespace.c:2787 ksys_mount+0x12d/0x140 fs/namespace.c:3003 __do_sys_mount fs/namespace.c:3017 [inline] __se_sys_mount fs/namespace.c:3014 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457569 Code: fd b3 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 cb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f941ce1fc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007f941ce1fc90 RCX: 0000000000457569 RDX: 0000000020000380 RSI: 00000000200002c0 RDI: 0000000000000000 RBP: 000000000072bf00 R08: 0000000020000740 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f941ce206d4 R13: 00000000004c28a1 R14: 00000000004d3c90 R15: 0000000000000005 Allocated by task 25700: 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 __do_kmalloc mm/slab.c:3718 [inline] __kmalloc+0x14e/0x760 mm/slab.c:3727 kmalloc include/linux/slab.h:518 [inline] kzalloc include/linux/slab.h:707 [inline] fscache_set_key fs/fscache/cookie.c:101 [inline] fscache_alloc_cookie+0x6f7/0x880 fs/fscache/cookie.c:171 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] v9fs_cache_session_get_cookie+0xc4/0x270 fs/9p/cache.c:73 v9fs_session_init+0xffe/0x1a70 fs/9p/v9fs.c:464 v9fs_mount+0x7d/0x8f0 fs/9p/vfs_super.c:135 mount_fs+0xae/0x31d fs/super.c:1261 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2457 [inline] do_mount+0x581/0x31f0 fs/namespace.c:2787 ksys_mount+0x12d/0x140 fs/namespace.c:3003 __do_sys_mount fs/namespace.c:3017 [inline] __se_sys_mount fs/namespace.c:3014 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe Freed by task 25700: 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:3813 fscache_free_cookie+0x230/0x280 fs/fscache/cookie.c:67 fscache_cookie_put+0x3a2/0x880 fs/fscache/cookie.c:889 __fscache_relinquish_cookie+0x4a7/0x91a fs/fscache/cookie.c:846 fscache_relinquish_cookie include/linux/fscache.h:367 [inline] v9fs_cache_session_put_cookie+0x46/0x90 fs/9p/cache.c:87 v9fs_session_close+0xf4/0x420 fs/9p/v9fs.c:498 v9fs_kill_super+0x4e/0xa0 fs/9p/vfs_super.c:233 deactivate_locked_super+0x97/0x100 fs/super.c:329 v9fs_mount+0x452/0x8f0 fs/9p/vfs_super.c:214 mount_fs+0xae/0x31d fs/super.c:1261 vfs_kern_mount.part.35+0xdc/0x4f0 fs/namespace.c:961 vfs_kern_mount fs/namespace.c:951 [inline] do_new_mount fs/namespace.c:2457 [inline] do_mount+0x581/0x31f0 fs/namespace.c:2787 ksys_mount+0x12d/0x140 fs/namespace.c:3003 __do_sys_mount fs/namespace.c:3017 [inline] __se_sys_mount fs/namespace.c:3014 [inline] __x64_sys_mount+0xbe/0x150 fs/namespace.c:3014 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 ffff8801c8ce6600 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 0 bytes inside of 64-byte region [ffff8801c8ce6600, ffff8801c8ce6640) The buggy address belongs to the page: page:ffffea0007233980 count:1 mapcount:0 mapping:ffff8801da800340 index:0x0 flags: 0x2fffc0000000100(slab) raw: 02fffc0000000100 ffffea00076397c8 ffffea000736c308 ffff8801da800340 raw: 0000000000000000 ffff8801c8ce6000 0000000100000020 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c8ce6500: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc ffff8801c8ce6580: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc >ffff8801c8ce6600: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff8801c8ce6680: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff8801c8ce6700: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc ==================================================================