================================================================== BUG: KASAN: slab-use-after-free in nr_dec_obs net/netrom/nr_route.c:471 [inline] BUG: KASAN: slab-use-after-free in nr_rt_ioctl+0x2583/0x29b0 net/netrom/nr_route.c:692 Read of size 4 at addr ffff888039be5330 by task syz.2.500/7541 CPU: 0 UID: 0 PID: 7541 Comm: syz.2.500 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 nr_dec_obs net/netrom/nr_route.c:471 [inline] nr_rt_ioctl+0x2583/0x29b0 net/netrom/nr_route.c:692 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2db038eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2db127a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f2db05e5fa0 RCX: 00007f2db038eec9 RDX: 0000000000000000 RSI: 00000000000089e2 RDI: 0000000000000007 RBP: 00007f2db0411f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2db05e6038 R14: 00007f2db05e5fa0 R15: 00007fff78547d48 Allocated by task 7542: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:957 [inline] nr_add_node+0xe4e/0x2c00 net/netrom/nr_route.c:146 nr_rt_ioctl+0x11b7/0x29b0 net/netrom/nr_route.c:651 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7541: kasan_save_stack+0x33/0x60 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6674 [inline] kfree+0x2f8/0x6e0 mm/slub.c:6882 nr_neigh_put include/net/netrom.h:143 [inline] nr_neigh_put include/net/netrom.h:137 [inline] nr_dec_obs net/netrom/nr_route.c:469 [inline] nr_rt_ioctl+0xbed/0x29b0 net/netrom/nr_route.c:692 nr_ioctl+0x19a/0x2d0 net/netrom/af_netrom.c:1254 sock_do_ioctl+0x118/0x280 net/socket.c:1254 sock_ioctl+0x227/0x6b0 net/socket.c:1375 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff888039be5300 which belongs to the cache kmalloc-64 of size 64 The buggy address is located 48 bytes inside of freed 64-byte region [ffff888039be5300, ffff888039be5340) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x39be5 flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000000 ffff88801b4428c0 dead000000000100 dead000000000122 raw: 0000000000000000 0000000080200020 00000000f5000000 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 0x52c40(GFP_NOFS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 6013, tgid 6013 (syz-executor), ts 71544812768, free_ts 71544108602 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5240 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c3/0x430 mm/slub.c:3302 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_noprof+0x4fc/0x910 mm/slub.c:5669 kmalloc_noprof include/linux/slab.h:961 [inline] kzalloc_noprof include/linux/slab.h:1094 [inline] tomoyo_encode2+0x100/0x3e0 security/tomoyo/realpath.c:45 tomoyo_encode+0x29/0x50 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x18f/0x6e0 security/tomoyo/realpath.c:283 tomoyo_mount_acl+0x1ae/0x850 security/tomoyo/mount.c:105 tomoyo_mount_permission+0x16d/0x420 security/tomoyo/mount.c:237 security_sb_mount+0x9b/0x260 security/security.c:1062 path_mount+0x158/0x23a0 fs/namespace.c:3964 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 page last free pid 6013 tgid 6013 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2973 selinux_genfs_get_sid security/selinux/hooks.c:1359 [inline] inode_doinit_with_dentry+0xaca/0x12e0 security/selinux/hooks.c:1557 sb_finish_set_opts+0x221/0xb80 security/selinux/hooks.c:589 selinux_set_mnt_opts+0xc52/0x18c0 security/selinux/hooks.c:877 security_sb_set_mnt_opts+0xc0/0x140 security/security.c:1114 vfs_get_tree+0x17a/0x330 fs/super.c:1776 fc_mount fs/namespace.c:1199 [inline] do_new_mount_fc fs/namespace.c:3636 [inline] do_new_mount fs/namespace.c:3712 [inline] path_mount+0x7bf/0x23a0 fs/namespace.c:4022 do_mount fs/namespace.c:4035 [inline] __do_sys_mount fs/namespace.c:4224 [inline] __se_sys_mount fs/namespace.c:4201 [inline] __x64_sys_mount+0x293/0x310 fs/namespace.c:4201 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888039be5200: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888039be5280: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff888039be5300: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ^ ffff888039be5380: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ffff888039be5400: fa fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc ==================================================================