================================================================== BUG: KASAN: slab-use-after-free in ecryptfs_write_tag_70_packet+0x117b/0x1410 fs/ecryptfs/keystore.c:742 Read of size 4 at addr ffff888050281c98 by task syz.1.18/6058 CPU: 2 UID: 0 PID: 6058 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1c0 mm/kasan/report.c:595 ecryptfs_write_tag_70_packet+0x117b/0x1410 fs/ecryptfs/keystore.c:742 ecryptfs_encrypt_filename fs/ecryptfs/crypto.c:1378 [inline] ecryptfs_encrypt_and_encode_filename+0x428/0xa60 fs/ecryptfs/crypto.c:1789 ecryptfs_lookup+0x1f7/0x830 fs/ecryptfs/inode.c:402 lookup_one_qstr_excl+0x1cd/0x250 fs/namei.c:1810 __start_dirop fs/namei.c:2920 [inline] start_dirop fs/namei.c:2942 [inline] filename_create+0x1cf/0x400 fs/namei.c:5102 filename_mkdirat+0xb9/0x5e0 fs/namei.c:5446 __do_sys_mkdirat fs/namei.c:5474 [inline] __se_sys_mkdirat fs/namei.c:5471 [inline] __ia32_sys_mkdirat+0x88/0xc0 fs/namei.c:5471 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e RIP: 0023:0xf7fd8fbc Code: d2 74 05 c1 e8 0c 89 02 8b 5d fc 31 c0 c9 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 2e 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00 58 b8 RSP: 002b:00000000f688e50c EFLAGS: 00000292 ORIG_RAX: 0000000000000128 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000080000100 RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000292 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Allocated by task 6058: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:409 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:426 kasan_kmalloc include/linux/kasan.h:263 [inline] __do_kmalloc_node mm/slub.c:5531 [inline] __kvmalloc_node_noprof+0x35b/0x9b0 mm/slub.c:7136 __do_sys_add_key+0x244/0x460 security/keys/keyctl.c:116 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e Freed by task 6058: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:264 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:296 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2780 [inline] slab_free mm/slub.c:6630 [inline] kfree+0x22b/0x6d0 mm/slub.c:6923 __do_sys_add_key+0x370/0x460 security/keys/keyctl.c:147 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:79 [inline] __do_fast_syscall_32+0x14b/0x8c0 arch/x86/entry/syscall_32.c:282 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:307 entry_SYSENTER_compat_after_hwframe+0x84/0x8e The buggy address belongs to the object at ffff888050281c00 which belongs to the cache kmalloc-256 of size 256 The buggy address is located 152 bytes inside of freed 256-byte region [ffff888050281c00, ffff888050281d00) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x50280 head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801d442b40 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 04fff00000000040 ffff88801d442b40 dead000000000100 dead000000000122 head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000 head: 04fff00000000001 ffffffffffffff81 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5963, tgid 5963 (syz-executor), ts 55232459828 set_page_owner include/linux/page_owner.h:33 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1854 prep_new_page mm/page_alloc.c:1862 [inline] get_page_from_freelist+0x1113/0x35e0 mm/page_alloc.c:3933 __alloc_frozen_pages_noprof+0x2f6/0x3190 mm/page_alloc.c:5429 alloc_slab_page mm/slub.c:3384 [inline] allocate_slab mm/slub.c:3499 [inline] new_slab+0xb1/0x6d0 mm/slub.c:3550 refill_objects+0xe3/0x410 mm/slub.c:7539 refill_sheaf mm/slub.c:2917 [inline] __pcs_replace_empty_main+0x35e/0x650 mm/slub.c:4811 alloc_from_pcs mm/slub.c:4887 [inline] slab_alloc_node mm/slub.c:5021 [inline] __do_kmalloc_node mm/slub.c:5530 [inline] __kmalloc_noprof+0x677/0x840 mm/slub.c:5556 _kmalloc_noprof include/linux/slab.h:995 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] fib_create_info+0x5bf/0x4640 net/ipv4/fib_semantics.c:1432 fib_table_insert+0x169/0x1c70 net/ipv4/fib_trie.c:1210 fib_magic+0x4d4/0x5c0 net/ipv4/fib_frontend.c:1147 fib_add_ifaddr+0x16d/0x560 net/ipv4/fib_frontend.c:1169 fib_netdev_event+0x3d6/0x710 net/ipv4/fib_frontend.c:1529 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:86 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2313 call_netdevice_notifiers_extack net/core/dev.c:2351 [inline] call_netdevice_notifiers net/core/dev.c:2365 [inline] __dev_notify_flags+0x22c/0x4b0 net/core/dev.c:10004 netif_change_flags+0x108/0x160 net/core/dev.c:10033 page last free pid 5214 tgid 5214 ts 16716438392 stack trace: reset_page_owner include/linux/page_owner.h:26 [inline] __free_pages_prepare mm/page_alloc.c:1401 [inline] __free_frozen_pages+0x7b4/0x1110 mm/page_alloc.c:2952 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:361 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4720 [inline] slab_alloc_node mm/slub.c:5033 [inline] __kmalloc_cache_noprof+0x278/0x6d0 mm/slub.c:5676 _kmalloc_noprof include/linux/slab.h:991 [inline] _kzalloc_noprof include/linux/slab.h:1312 [inline] uevent_show+0x166/0x3a0 drivers/base/core.c:2825 dev_attr_show+0x52/0xa0 drivers/base/core.c:2491 sysfs_kf_seq_show+0x217/0x3f0 fs/sysfs/file.c:65 seq_read_iter+0x32f/0x1270 fs/seq_file.c:231 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:290 new_sync_read fs/read_write.c:493 [inline] vfs_read+0x82e/0xb40 fs/read_write.c:574 ksys_read+0x12a/0x250 fs/read_write.c:716 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline] do_syscall_64+0x121/0x770 arch/x86/entry/syscall_64.c:84 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888050281b80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888050281c00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888050281c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888050281d00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888050281d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ================================================================== ---------------- Code disassembly (best guess): 0: d2 74 05 c1 shlb %cl,-0x3f(%rbp,%rax,1) 4: e8 0c 89 02 8b call 0x8b028915 9: 5d pop %rbp a: fc cld b: 31 c0 xor %eax,%eax d: c9 leave e: c3 ret f: 90 nop 10: 90 nop 11: 90 nop 12: 90 nop 13: 90 nop 14: 90 nop 15: 90 nop 16: 90 nop 17: 90 nop 18: 90 nop 19: 90 nop 1a: 90 nop 1b: 90 nop 1c: 90 nop 1d: 90 nop 1e: 0f 1f 00 nopl (%rax) 21: 51 push %rcx 22: 52 push %rdx 23: 55 push %rbp 24: 89 e5 mov %esp,%ebp 26: 0f 34 sysenter 28: cd 80 int $0x80 * 2a: 5d pop %rbp <-- trapping instruction 2b: 5a pop %rdx 2c: 59 pop %rcx 2d: c3 ret 2e: 90 nop 2f: 2e 8d b4 26 00 00 00 cs lea 0x0(%rsi,%riz,1),%esi 36: 00 37: 8d b4 26 00 00 00 00 lea 0x0(%rsi,%riz,1),%esi 3e: 58 pop %rax 3f: b8 .byte 0xb8