================================================================== BUG: KASAN: use-after-free in skb_end_pointer include/linux/skbuff.h:1424 [inline] BUG: KASAN: use-after-free in kcm_sendpage+0x146a/0x1630 net/kcm/kcmsock.c:785 Read of size 8 at addr ffff88801fcc6848 by task syz-executor.5/15080 CPU: 0 PID: 15080 Comm: syz-executor.5 Not tainted 5.13.0-rc3-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x141/0x1d7 lib/dump_stack.c:120 print_address_description.constprop.0.cold+0x5b/0x2f8 mm/kasan/report.c:233 __kasan_report mm/kasan/report.c:419 [inline] kasan_report.cold+0x7c/0xd8 mm/kasan/report.c:436 skb_end_pointer include/linux/skbuff.h:1424 [inline] kcm_sendpage+0x146a/0x1630 net/kcm/kcmsock.c:785 kernel_sendpage.part.0+0x1ab/0x350 net/socket.c:3631 kernel_sendpage net/socket.c:3628 [inline] sock_sendpage+0xe5/0x140 net/socket.c:947 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0x9f0/0x1110 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1311 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x4665d9 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 bc ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb6fd5ad188 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 000000000056c260 RCX: 00000000004665d9 RDX: 0000000000000000 RSI: 0000000000000005 RDI: 0000000000000007 RBP: 00000000004bfcb9 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000100000001 R11: 0000000000000246 R12: 000000000056c260 R13: 00007ffc0cbace9f R14: 00007fb6fd5ad300 R15: 0000000000022000 Allocated by task 15080: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track mm/kasan/common.c:46 [inline] set_alloc_info mm/kasan/common.c:428 [inline] __kasan_slab_alloc+0x84/0xa0 mm/kasan/common.c:461 kasan_slab_alloc include/linux/kasan.h:236 [inline] slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:2913 [inline] kmem_cache_alloc_node+0x269/0x3e0 mm/slub.c:2949 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1112 [inline] kcm_sendpage+0x3db/0x1630 net/kcm/kcmsock.c:796 kernel_sendpage.part.0+0x1ab/0x350 net/socket.c:3631 kernel_sendpage net/socket.c:3628 [inline] sock_sendpage+0xe5/0x140 net/socket.c:947 pipe_to_sendpage+0x2ad/0x380 fs/splice.c:364 splice_from_pipe_feed fs/splice.c:418 [inline] __splice_from_pipe+0x43e/0x8a0 fs/splice.c:562 splice_from_pipe fs/splice.c:597 [inline] generic_splice_sendpage+0xd4/0x140 fs/splice.c:746 do_splice_from fs/splice.c:767 [inline] direct_splice_actor+0x110/0x180 fs/splice.c:936 splice_direct_to_actor+0x34b/0x8c0 fs/splice.c:891 do_splice_direct+0x1b3/0x280 fs/splice.c:979 do_sendfile+0x9f0/0x1110 fs/read_write.c:1260 __do_sys_sendfile64 fs/read_write.c:1325 [inline] __se_sys_sendfile64 fs/read_write.c:1311 [inline] __x64_sys_sendfile64+0x1cc/0x210 fs/read_write.c:1311 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Freed by task 15079: kasan_save_stack+0x1b/0x40 mm/kasan/common.c:38 kasan_set_track+0x1c/0x30 mm/kasan/common.c:46 kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:357 ____kasan_slab_free mm/kasan/common.c:360 [inline] ____kasan_slab_free mm/kasan/common.c:325 [inline] __kasan_slab_free+0xfb/0x130 mm/kasan/common.c:368 kasan_slab_free include/linux/kasan.h:212 [inline] slab_free_hook mm/slub.c:1582 [inline] slab_free_freelist_hook+0xdf/0x240 mm/slub.c:1607 slab_free mm/slub.c:3167 [inline] kmem_cache_free+0x8a/0x740 mm/slub.c:3183 kfree_skbmem+0xef/0x1b0 net/core/skbuff.c:688 __kfree_skb net/core/skbuff.c:745 [inline] kfree_skb net/core/skbuff.c:762 [inline] kfree_skb+0x140/0x3f0 net/core/skbuff.c:756 kfree_skb_list+0x3f/0x60 net/core/skbuff.c:771 kcm_sendmsg+0xe65/0x2240 net/kcm/kcmsock.c:1070 sock_sendmsg_nosec net/socket.c:654 [inline] sock_sendmsg+0xcf/0x120 net/socket.c:674 sock_write_iter+0x289/0x3c0 net/socket.c:1001 call_write_iter include/linux/fs.h:2114 [inline] new_sync_write+0x426/0x650 fs/read_write.c:518 vfs_write+0x796/0xa30 fs/read_write.c:605 ksys_write+0x1ee/0x250 fs/read_write.c:658 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae The buggy address belongs to the object at ffff88801fcc6780 which belongs to the cache skbuff_head_cache of size 232 The buggy address is located 200 bytes inside of 232-byte region [ffff88801fcc6780, ffff88801fcc6868) The buggy address belongs to the page: page:ffffea00007f3180 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1fcc6 flags: 0xfff00000000200(slab|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000000200 ffffea00009d1b80 0000000600000006 ffff88814398a640 raw: 0000000000000000 00000000000c000c 00000001ffffffff 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 0x12a20(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY), pid 8427, ts 164999414940, free_ts 158386763336 prep_new_page mm/page_alloc.c:2358 [inline] get_page_from_freelist+0x1034/0x2bf0 mm/page_alloc.c:3994 __alloc_pages+0x1b2/0x500 mm/page_alloc.c:5200 alloc_pages+0x18c/0x2a0 mm/mempolicy.c:2272 alloc_slab_page mm/slub.c:1645 [inline] allocate_slab+0x32e/0x4c0 mm/slub.c:1785 new_slab mm/slub.c:1848 [inline] new_slab_objects mm/slub.c:2594 [inline] ___slab_alloc+0x4a1/0x810 mm/slub.c:2757 __slab_alloc.constprop.0+0xa7/0xf0 mm/slub.c:2797 slab_alloc_node mm/slub.c:2879 [inline] kmem_cache_alloc_node+0x12f/0x3e0 mm/slub.c:2949 __alloc_skb+0x20b/0x340 net/core/skbuff.c:414 alloc_skb include/linux/skbuff.h:1112 [inline] __tcp_send_ack.part.0+0x67/0x7a0 net/ipv4/tcp_output.c:3944 __tcp_send_ack net/ipv4/tcp_output.c:3976 [inline] tcp_send_ack+0x7d/0xa0 net/ipv4/tcp_output.c:3976 tcp_cleanup_rbuf+0x46c/0x5b0 net/ipv4/tcp.c:1598 tcp_recvmsg_locked+0x7aa/0x22f0 net/ipv4/tcp.c:2519 tcp_recvmsg+0x134/0x550 net/ipv4/tcp.c:2549 inet_recvmsg+0x11b/0x5d0 net/ipv4/af_inet.c:852 sock_recvmsg_nosec net/socket.c:888 [inline] sock_recvmsg net/socket.c:906 [inline] sock_recvmsg net/socket.c:902 [inline] sock_read_iter+0x33c/0x470 net/socket.c:979 call_read_iter include/linux/fs.h:2108 [inline] new_sync_read+0x5b7/0x6e0 fs/read_write.c:415 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1298 [inline] free_pcp_prepare+0x223/0x300 mm/page_alloc.c:1342 free_unref_page_prepare mm/page_alloc.c:3250 [inline] free_unref_page+0x12/0x1d0 mm/page_alloc.c:3298 unfreeze_partials+0x17c/0x1d0 mm/slub.c:2375 put_cpu_partial+0x13d/0x230 mm/slub.c:2411 qlink_free mm/kasan/quarantine.c:146 [inline] qlist_free_all+0x5a/0xc0 mm/kasan/quarantine.c:165 kasan_quarantine_reduce+0x180/0x200 mm/kasan/quarantine.c:272 __kasan_slab_alloc+0x8e/0xa0 mm/kasan/common.c:438 kasan_slab_alloc include/linux/kasan.h:236 [inline] slab_post_alloc_hook mm/slab.h:524 [inline] slab_alloc_node mm/slub.c:2913 [inline] slab_alloc mm/slub.c:2921 [inline] __kmalloc+0x1f7/0x330 mm/slub.c:4055 kmalloc include/linux/slab.h:561 [inline] tomoyo_add_entry security/tomoyo/common.c:2031 [inline] tomoyo_supervisor+0xce8/0xf00 security/tomoyo/common.c:2103 tomoyo_audit_path_log security/tomoyo/file.c:168 [inline] tomoyo_path_permission security/tomoyo/file.c:587 [inline] tomoyo_path_permission+0x270/0x3a0 security/tomoyo/file.c:573 tomoyo_path_perm+0x2f0/0x400 security/tomoyo/file.c:838 security_inode_getattr+0xcf/0x140 security/security.c:1332 vfs_getattr fs/stat.c:139 [inline] vfs_fstat+0x43/0xb0 fs/stat.c:164 __do_sys_newfstat+0x81/0x100 fs/stat.c:404 do_syscall_64+0x3a/0xb0 arch/x86/entry/common.c:47 entry_SYSCALL_64_after_hwframe+0x44/0xae Memory state around the buggy address: ffff88801fcc6700: fb fb fb fb fb fc fc fc fc fc fc fc fc fc fc fc ffff88801fcc6780: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88801fcc6800: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc ^ ffff88801fcc6880: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb ffff88801fcc6900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================