================================================================== BUG: KASAN: slab-out-of-bounds in fscache_set_key fs/fscache/cookie.c:120 [inline] BUG: KASAN: slab-out-of-bounds in fscache_alloc_cookie+0x745/0x800 fs/fscache/cookie.c:171 Read of size 4 at addr ffff8801c2963214 by task syz-executor5/9044 CPU: 0 PID: 9044 Comm: syz-executor5 Not tainted 4.19.0-rc8-next-20181017+ #96 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+0x244/0x39d lib/dump_stack.c:113 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report.cold.8+0x242/0x309 mm/kasan/report.c:412 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432 fscache_set_key fs/fscache/cookie.c:120 [inline] fscache_alloc_cookie+0x745/0x800 fs/fscache/cookie.c:171 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] nfs_fscache_get_client_cookie+0x463/0x600 fs/nfs/fscache.c:85 nfs_alloc_client+0x4de/0x770 fs/nfs/client.c:188 nfs_get_client+0x8e8/0x14c0 fs/nfs/client.c:430 nfs_init_server+0x357/0xff0 fs/nfs/client.c:670 nfs_create_server+0x86/0x5f0 fs/nfs/client.c:954 nfs_try_mount+0x180/0xa80 fs/nfs/super.c:1885 nfs_fs_mount+0x185f/0x2f36 fs/nfs/super.c:2697 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: 0033:0x457569 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:00007f5f1affcc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 0000000000457569 RDX: 000000002015bffc RSI: 0000000020343ff8 RDI: 00000000208deff8 RBP: 000000000072bf00 R08: 000000002000a000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5f1affd6d4 R13: 00000000004c289b R14: 00000000004d3c78 R15: 00000000ffffffff Allocated by task 9044: 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:3722 [inline] __kmalloc+0x15b/0x760 mm/slab.c:3731 kmalloc include/linux/slab.h:551 [inline] kzalloc include/linux/slab.h:741 [inline] fscache_set_key fs/fscache/cookie.c:101 [inline] fscache_alloc_cookie+0x68f/0x800 fs/fscache/cookie.c:171 __fscache_acquire_cookie+0x230/0xb60 fs/fscache/cookie.c:303 fscache_acquire_cookie include/linux/fscache.h:338 [inline] nfs_fscache_get_client_cookie+0x463/0x600 fs/nfs/fscache.c:85 nfs_alloc_client+0x4de/0x770 fs/nfs/client.c:188 nfs_get_client+0x8e8/0x14c0 fs/nfs/client.c:430 nfs_init_server+0x357/0xff0 fs/nfs/client.c:670 nfs_create_server+0x86/0x5f0 fs/nfs/client.c:954 nfs_try_mount+0x180/0xa80 fs/nfs/super.c:1885 nfs_fs_mount+0x185f/0x2f36 fs/nfs/super.c:2697 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 7572: 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 kfree_const+0x59/0x70 mm/util.c:38 kobject_cleanup lib/kobject.c:668 [inline] kobject_release lib/kobject.c:691 [inline] kref_put include/linux/kref.h:70 [inline] kobject_put.cold.9+0x2b1/0x2e4 lib/kobject.c:708 net_rx_queue_update_kobjects+0x42e/0x620 net/core/net-sysfs.c:978 remove_queue_kobjects net/core/net-sysfs.c:1562 [inline] netdev_unregister_kobject+0x1f2/0x2e0 net/core/net-sysfs.c:1713 rollback_registered_many+0x8d4/0x1250 net/core/dev.c:8026 rollback_registered+0x1e9/0x420 net/core/dev.c:8044 unregister_netdevice_queue+0x321/0x5e0 net/core/dev.c:9088 unregister_netdevice include/linux/netdevice.h:2637 [inline] ppp_release+0x1c9/0x1f0 drivers/net/ppp/ppp_generic.c:409 __fput+0x3bc/0xa70 fs/file_table.c:279 ____fput+0x15/0x20 fs/file_table.c:312 task_work_run+0x1e8/0x2a0 kernel/task_work.c:113 get_signal+0x1550/0x1970 kernel/signal.c:2347 do_signal+0x9c/0x21c0 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x2e5/0x380 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x6be/0x820 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe The buggy address belongs to the object at ffff8801c2963200 which belongs to the cache kmalloc-32 of size 32 The buggy address is located 20 bytes inside of 32-byte region [ffff8801c2963200, ffff8801c2963220) The buggy address belongs to the page: page:ffffea00070a58c0 count:1 mapcount:0 mapping:ffff8801da8001c0 index:0xffff8801c2963fc1 flags: 0x2fffc0000000200(slab) raw: 02fffc0000000200 ffffea0007568188 ffffea00070c5788 ffff8801da8001c0 raw: ffff8801c2963fc1 ffff8801c2963000 000000010000003f 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8801c2963100: 00 fc fc fc fc fc fc fc fb fb fb fb fc fc fc fc ffff8801c2963180: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc >ffff8801c2963200: 00 00 06 fc fc fc fc fc 01 fc fc fc fc fc fc fc ^ ffff8801c2963280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ffff8801c2963300: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc ==================================================================