CIFS: Attempting to mount //127.0.0.1/share ================================================================== BUG: KASAN: slab-use-after-free in cifs_free_hash+0xcc/0x100 fs/smb/client/misc.c:1216 Write of size 8 at addr ffff8880770b8468 by task syz.3.3473/18162 CPU: 1 PID: 18162 Comm: syz.3.3473 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 Call Trace: dump_stack_lvl+0x18c/0x250 lib/dump_stack.c:106 print_address_description mm/kasan/report.c:364 [inline] print_report+0xa8/0x210 mm/kasan/report.c:468 kasan_report+0x117/0x150 mm/kasan/report.c:581 cifs_free_hash+0xcc/0x100 fs/smb/client/misc.c:1216 cifs_crypto_secmech_release+0x32/0x110 fs/smb/client/cifsencrypt.c:847 cifs_put_tcp_session+0x20b/0x320 fs/smb/client/connect.c:1706 cifs_mount_put_conns+0xb4/0x280 fs/smb/client/connect.c:3453 cifs_mount+0xdc/0x650 fs/smb/client/connect.c:3764 cifs_smb3_do_mount+0x2e5/0x710 fs/smb/client/cifsfs.c:950 smb3_get_tree_common fs/smb/client/fs_context.c:785 [inline] smb3_get_tree+0x5a5/0xa90 fs/smb/client/fs_context.c:805 vfs_get_tree+0x8c/0x280 fs/super.c:1772 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fbbc519e159 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fbbc6095028 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5 RAX: ffffffffffffffda RBX: 00007fbbc5426180 RCX: 00007fbbc519e159 RDX: 0000200000000400 RSI: 0000200000000300 RDI: 0000200000000200 RBP: 00007fbbc523506b R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000012 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fbbc5426218 R14: 00007fbbc5426180 R15: 00007fff61a6b158 Allocated by task 18162: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 ____kasan_kmalloc mm/kasan/common.c:375 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:384 kmalloc include/linux/slab.h:600 [inline] kzalloc include/linux/slab.h:721 [inline] cifs_get_tcp_session+0xb5/0x1a00 fs/smb/client/connect.c:1731 cifs_mount_get_session+0xae/0x440 fs/smb/client/connect.c:3478 get_session fs/smb/client/dfs.c:62 [inline] dfs_mount_share+0x1e9/0x7b0 fs/smb/client/dfs.c:285 cifs_mount+0xbc/0x650 fs/smb/client/connect.c:3734 cifs_smb3_do_mount+0x2e5/0x710 fs/smb/client/cifsfs.c:950 smb3_get_tree_common fs/smb/client/fs_context.c:785 [inline] smb3_get_tree+0x5a5/0xa90 fs/smb/client/fs_context.c:805 vfs_get_tree+0x8c/0x280 fs/super.c:1772 do_new_mount+0x24a/0xa40 fs/namespace.c:3386 do_mount fs/namespace.c:3726 [inline] __do_sys_mount fs/namespace.c:3935 [inline] __se_sys_mount+0x2e7/0x3d0 fs/namespace.c:3912 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 Freed by task 18163: kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 kasan_save_free_info+0x28/0x40 mm/kasan/generic.c:522 ____kasan_slab_free+0x126/0x1f0 mm/kasan/common.c:237 kasan_slab_free include/linux/kasan.h:164 [inline] slab_free_hook mm/slub.c:1811 [inline] slab_free_freelist_hook+0x130/0x1a0 mm/slub.c:1837 slab_free mm/slub.c:3830 [inline] __kmem_cache_free+0xba/0x1f0 mm/slub.c:3843 clean_demultiplex_info+0xb6f/0xd70 fs/smb/client/connect.c:1085 cifs_demultiplex_thread+0x274e/0x2a70 fs/smb/client/connect.c:1380 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 The buggy address belongs to the object at ffff8880770b8000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 1128 bytes inside of freed 4096-byte region [ffff8880770b8000, ffff8880770b9000) The buggy address belongs to the physical page: page:ffffea0001dc2e00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x770b8 head:ffffea0001dc2e00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0xfff00000000840(slab|head|node=0|zone=1|lastcpupid=0x7ff) page_type: 0xffffffff() raw: 00fff00000000840 ffff888017c42140 0000000000000000 dead000000000001 raw: 0000000000000000 0000000000040004 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0x1d2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 33, tgid 33 (kworker/u4:2), ts 186561645996, free_ts 186419229144 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x1c1/0x200 mm/page_alloc.c:1582 prep_new_page mm/page_alloc.c:1589 [inline] get_page_from_freelist+0x2181/0x22a0 mm/page_alloc.c:3221 __alloc_pages+0x1f0/0x460 mm/page_alloc.c:4501 alloc_slab_page+0x5d/0x180 mm/slub.c:1881 allocate_slab mm/slub.c:2028 [inline] new_slab+0x87/0x2d0 mm/slub.c:2081 ___slab_alloc+0xc5c/0x12f0 mm/slub.c:3253 __slab_alloc mm/slub.c:3339 [inline] __slab_alloc_node mm/slub.c:3392 [inline] slab_alloc_node mm/slub.c:3485 [inline] __kmem_cache_alloc_node+0x11f/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc_node_track_caller+0xa4/0x230 mm/slab_common.c:1027 kmalloc_reserve+0x116/0x240 net/core/skbuff.c:584 __alloc_skb+0x138/0x2c0 net/core/skbuff.c:653 alloc_skb include/linux/skbuff.h:1316 [inline] nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:748 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:805 [inline] nsim_dev_trap_report_work+0x253/0xa90 drivers/net/netdevsim/dev.c:851 process_one_work kernel/workqueue.c:2657 [inline] process_scheduled_works+0xa60/0x1600 kernel/workqueue.c:2734 worker_thread+0xa5e/0xfe0 kernel/workqueue.c:2815 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 discard_slab mm/slub.c:2127 [inline] __unfreeze_partials+0x1cf/0x210 mm/slub.c:2667 put_cpu_partial+0x17c/0x250 mm/slub.c:2743 __slab_free+0x319/0x400 mm/slub.c:3700 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3495 [inline] slab_alloc mm/slub.c:3503 [inline] __kmem_cache_alloc_lru mm/slub.c:3510 [inline] kmem_cache_alloc+0x17e/0x2c0 mm/slub.c:3519 ptlock_alloc+0x20/0x70 mm/memory.c:6177 ptlock_init include/linux/mm.h:2964 [inline] pagetable_pte_ctor include/linux/mm.h:2987 [inline] __pte_alloc_one include/asm-generic/pgalloc.h:71 [inline] pte_alloc_one+0xcc/0x540 arch/x86/mm/pgtable.c:33 __pte_alloc+0x22/0x2a0 mm/memory.c:438 do_anonymous_page mm/memory.c:4120 [inline] do_pte_missing mm/memory.c:3687 [inline] handle_pte_fault mm/memory.c:5047 [inline] __handle_mm_fault mm/memory.c:5188 [inline] handle_mm_fault+0x3dc6/0x4a50 mm/memory.c:5353 do_user_addr_fault+0xad2/0x12d0 arch/x86/mm/fault.c:1322 handle_page_fault arch/x86/mm/fault.c:1463 [inline] exc_page_fault+0x64/0x100 arch/x86/mm/fault.c:1516 Memory state around the buggy address: ffff8880770b8300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880770b8380: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff8880770b8400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8880770b8480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff8880770b8500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================