================================================================== BUG: KASAN: slab-use-after-free in memcmp+0x1b5/0x1c0 lib/string.c:681 Read of size 8 at addr ffff8880246a5500 by task syz-executor.3/27230 CPU: 2 PID: 27230 Comm: syz-executor.3 Not tainted 6.5.0-syzkaller-00607-g42a7f6e3ffe0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xc4/0x620 mm/kasan/report.c:475 kasan_report+0xda/0x110 mm/kasan/report.c:588 memcmp+0x1b5/0x1c0 lib/string.c:681 memcmp include/linux/fortify-string.h:728 [inline] compare_mount_options fs/ceph/super.c:622 [inline] ceph_compare_super+0x11a/0x8d0 fs/ceph/super.c:1147 sget_fc+0x582/0x9b0 fs/super.c:778 ceph_get_tree+0x6ea/0x1910 fs/ceph/super.c:1232 vfs_get_tree+0x8c/0x370 fs/super.c:1711 vfs_cmd_create+0x11f/0x2f0 fs/fsopen.c:230 vfs_fsconfig_locked fs/fsopen.c:294 [inline] __do_sys_fsconfig+0x832/0xb90 fs/fsopen.c:475 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f8ecb27cae9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 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 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f8ecc0c00c8 EFLAGS: 00000246 ORIG_RAX: 00000000000001af RAX: ffffffffffffffda RBX: 00007f8ecb39bf80 RCX: 00007f8ecb27cae9 RDX: 0000000000000000 RSI: 0000000000000006 RDI: 0000000000000003 RBP: 00007f8ecb2c847a R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f8ecb39bf80 R15: 00007fffd89fcd88 Allocated by task 27223: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 ____kasan_kmalloc mm/kasan/common.c:374 [inline] __kasan_kmalloc+0xa3/0xb0 mm/kasan/common.c:383 kmalloc include/linux/slab.h:582 [inline] kzalloc include/linux/slab.h:703 [inline] ceph_init_fs_context+0xc8/0x530 fs/ceph/super.c:1333 alloc_fs_context+0x56c/0x9f0 fs/fs_context.c:294 __do_sys_fsopen fs/fsopen.c:137 [inline] __se_sys_fsopen fs/fsopen.c:115 [inline] __x64_sys_fsopen+0xeb/0x230 fs/fsopen.c:115 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 27223: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x13f/0x190 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] __cache_free mm/slab.c:3370 [inline] __do_kmem_cache_free mm/slab.c:3557 [inline] __kmem_cache_free+0xcc/0x2d0 mm/slab.c:3564 destroy_mount_options fs/ceph/super.c:599 [inline] destroy_mount_options+0xe9/0x140 fs/ceph/super.c:588 destroy_fs_client+0x1b6/0x2b0 fs/ceph/super.c:860 deactivate_locked_super+0xa0/0x2d0 fs/super.c:454 ceph_get_tree+0x1270/0x1910 fs/ceph/super.c:1267 vfs_get_tree+0x8c/0x370 fs/super.c:1711 vfs_cmd_create+0x11f/0x2f0 fs/fsopen.c:230 vfs_fsconfig_locked fs/fsopen.c:294 [inline] __do_sys_fsconfig+0x832/0xb90 fs/fsopen.c:475 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Last potentially related work creation: kasan_save_stack+0x33/0x50 mm/kasan/common.c:45 __kasan_record_aux_stack+0x78/0x80 mm/kasan/generic.c:492 kvfree_call_rcu+0x70/0xbe0 kernel/rcu/tree.c:3372 cfg80211_update_known_bss+0x821/0xa80 net/wireless/scan.c:1744 __cfg80211_bss_update+0x1ba/0x2530 net/wireless/scan.c:1788 cfg80211_inform_single_bss_frame_data+0x7e7/0xf30 net/wireless/scan.c:2881 cfg80211_inform_bss_frame_data+0xbf/0x290 net/wireless/scan.c:2912 ieee80211_bss_info_update+0x37b/0x9a0 net/mac80211/scan.c:211 ieee80211_rx_bss_info net/mac80211/ibss.c:1124 [inline] ieee80211_rx_mgmt_probe_beacon net/mac80211/ibss.c:1613 [inline] ieee80211_ibss_rx_queued_mgmt+0x195f/0x2ee0 net/mac80211/ibss.c:1642 ieee80211_iface_process_skb net/mac80211/iface.c:1604 [inline] ieee80211_iface_work+0xa1f/0xd40 net/mac80211/iface.c:1658 cfg80211_wiphy_work+0x24e/0x330 net/wireless/core.c:435 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 The buggy address belongs to the object at ffff8880246a5500 which belongs to the cache kmalloc-96 of size 96 The buggy address is located 0 bytes inside of freed 96-byte region [ffff8880246a5500, ffff8880246a5560) The buggy address belongs to the physical page: page:ffffea000091a940 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff8880246a5a80 pfn:0x246a5 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) page_type: 0x1e() raw: 00fff00000000200 ffff888012840300 ffffea000095efd0 ffffea0000b440d0 raw: ffff8880246a5a80 ffff8880246a5000 000000010000001e 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 0, migratetype Unmovable, gfp_mask 0x3420c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_COMP|__GFP_HARDWALL|__GFP_THISNODE), pid 5296, tgid 5284 (syz-executor.1), ts 123456421589, free_ts 123422079323 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x2d2/0x350 mm/page_alloc.c:1570 prep_new_page mm/page_alloc.c:1577 [inline] get_page_from_freelist+0x10a9/0x31e0 mm/page_alloc.c:3221 __alloc_pages+0x1d0/0x4a0 mm/page_alloc.c:4477 __alloc_pages_node include/linux/gfp.h:237 [inline] kmem_getpages mm/slab.c:1356 [inline] cache_grow_begin+0x99/0x3a0 mm/slab.c:2550 cache_alloc_refill+0x294/0x3a0 mm/slab.c:2923 ____cache_alloc mm/slab.c:2999 [inline] ____cache_alloc mm/slab.c:2982 [inline] __do_cache_alloc mm/slab.c:3185 [inline] slab_alloc_node mm/slab.c:3230 [inline] __kmem_cache_alloc_node+0x38e/0x470 mm/slab.c:3521 __do_kmalloc_node mm/slab_common.c:984 [inline] __kmalloc_node+0x4f/0x100 mm/slab_common.c:992 kmalloc_array_node include/linux/slab.h:680 [inline] kcalloc_node include/linux/slab.h:685 [inline] memcg_alloc_slab_cgroups+0x10e/0x200 mm/memcontrol.c:2899 memcg_slab_post_alloc_hook+0xa9/0x350 mm/slab.h:530 slab_post_alloc_hook mm/slab.h:770 [inline] slab_alloc_node mm/slab.c:3237 [inline] slab_alloc mm/slab.c:3246 [inline] __kmem_cache_alloc_lru mm/slab.c:3423 [inline] kmem_cache_alloc_lru+0x233/0x680 mm/slab.c:3439 __d_alloc+0x32/0xac0 fs/dcache.c:1768 d_alloc_pseudo+0x1c/0x70 fs/dcache.c:1898 alloc_file_pseudo+0xdc/0x240 fs/file_table.c:329 __anon_inode_getfile+0x136/0x3d0 fs/anon_inodes.c:109 __anon_inode_getfd fs/anon_inodes.c:194 [inline] anon_inode_getfd+0x52/0xa0 fs/anon_inodes.c:229 create_vcpu_fd arch/x86/kvm/../../../virt/kvm/kvm_main.c:3869 [inline] kvm_vm_ioctl_create_vcpu arch/x86/kvm/../../../virt/kvm/kvm_main.c:3977 [inline] kvm_vm_ioctl+0x1e33/0x2770 arch/x86/kvm/../../../virt/kvm/kvm_main.c:4765 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1161 [inline] free_unref_page_prepare+0x508/0xb90 mm/page_alloc.c:2348 free_unref_page+0x33/0x3b0 mm/page_alloc.c:2443 vfree+0x181/0x7a0 mm/vmalloc.c:2842 delayed_vfree_work+0x56/0x70 mm/vmalloc.c:2763 process_one_work+0xaa2/0x16f0 kernel/workqueue.c:2600 worker_thread+0x687/0x1110 kernel/workqueue.c:2751 kthread+0x33a/0x430 kernel/kthread.c:389 ret_from_fork+0x2c/0x70 arch/x86/kernel/process.c:145 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:304 Memory state around the buggy address: ffff8880246a5400: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880246a5480: 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc >ffff8880246a5500: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ^ ffff8880246a5580: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc ffff8880246a5600: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc ==================================================================