vcan0: j1939_xtp_rx_dat_one: 0xffff88801cfb4800: last 15 vcan0: j1939_xtp_rx_dat_one: 0xffff88802ab67000: last 15 vcan0: j1939_xtp_rx_dat_one: 0xffff88801cfb4800: last 15 vcan0: j1939_xtp_rx_dat_one: 0xffff88802ab67000: last 15 ================================================================== BUG: KASAN: slab-use-after-free in skb_zcopy include/linux/skbuff.h:1651 [inline] BUG: KASAN: slab-use-after-free in skb_release_data+0x735/0x820 net/core/skbuff.c:884 Read of size 1 at addr ffff88807a46eec0 by task ksoftirqd/0/15 CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.3.0-rc6-syzkaller-g09a9639e56c0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/30/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 print_address_description.constprop.0+0x2c/0x3c0 mm/kasan/report.c:319 print_report mm/kasan/report.c:430 [inline] kasan_report+0x11c/0x130 mm/kasan/report.c:536 skb_zcopy include/linux/skbuff.h:1651 [inline] skb_release_data+0x735/0x820 net/core/skbuff.c:884 skb_release_all net/core/skbuff.c:964 [inline] __kfree_skb net/core/skbuff.c:978 [inline] consume_skb net/core/skbuff.c:1191 [inline] consume_skb+0xd0/0x170 net/core/skbuff.c:1185 j1939_xtp_rx_dat_one+0x8b9/0xea0 net/can/j1939/transport.c:1914 j1939_xtp_rx_dat net/can/j1939/transport.c:1940 [inline] j1939_tp_recv+0x7d5/0xf50 net/can/j1939/transport.c:2134 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa80 net/can/j1939/main.c:38 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606 can_receive+0x31d/0x5c0 net/can/af_can.c:663 can_rcv+0x1e1/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5479 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5593 process_backlog+0x239/0x800 net/core/dev.c:5921 __napi_poll+0xb7/0x6f0 net/core/dev.c:6482 napi_poll net/core/dev.c:6549 [inline] net_rx_action+0x9c2/0xd80 net/core/dev.c:6659 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 run_ksoftirqd kernel/softirq.c:934 [inline] run_ksoftirqd+0x31/0x60 kernel/softirq.c:926 smpboot_thread_fn+0x659/0x9e0 kernel/smpboot.c:164 kthread+0x2e8/0x3a0 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Allocated by task 7689: kasan_save_stack+0x22/0x40 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 mm/kasan/common.c:333 [inline] __kasan_kmalloc+0xa2/0xb0 mm/kasan/common.c:383 kasan_kmalloc include/linux/kasan.h:196 [inline] __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc_node_track_caller+0x5f/0x1a0 mm/slab_common.c:987 kmalloc_reserve+0xf0/0x270 net/core/skbuff.c:537 __alloc_skb+0x129/0x330 net/core/skbuff.c:606 alloc_skb include/linux/skbuff.h:1277 [inline] alloc_skb_with_frags+0x97/0x6c0 net/core/skbuff.c:6318 sock_alloc_send_pskb+0x7a7/0x930 net/core/sock.c:2734 sock_alloc_send_skb include/net/sock.h:1860 [inline] j1939_sk_alloc_skb net/can/j1939/socket.c:864 [inline] j1939_sk_send_loop net/can/j1939/socket.c:1121 [inline] j1939_sk_sendmsg+0x6ba/0x13a0 net/can/j1939/socket.c:1256 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 sock_no_sendpage+0x10c/0x160 net/core/sock.c:3235 kernel_sendpage.part.0+0x1d5/0x700 net/socket.c:3580 kernel_sendpage net/socket.c:3577 [inline] sock_sendpage+0xe7/0x180 net/socket.c:1080 pipe_to_sendpage+0x2b1/0x380 fs/splice.c:454 splice_from_pipe_feed fs/splice.c:508 [inline] __splice_from_pipe+0x449/0x8a0 fs/splice.c:652 splice_from_pipe fs/splice.c:687 [inline] generic_splice_sendpage+0xd8/0x140 fs/splice.c:835 do_splice_from fs/splice.c:856 [inline] direct_splice_actor+0x114/0x180 fs/splice.c:1022 splice_direct_to_actor+0x335/0x8a0 fs/splice.c:977 do_splice_direct+0x1ab/0x280 fs/splice.c:1065 do_sendfile+0xb19/0x12c0 fs/read_write.c:1255 __do_sys_sendfile64 fs/read_write.c:1323 [inline] __se_sys_sendfile64 fs/read_write.c:1309 [inline] __x64_sys_sendfile64+0x1d0/0x210 fs/read_write.c:1309 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Freed by task 21: kasan_save_stack+0x22/0x40 mm/kasan/common.c:45 kasan_set_track+0x25/0x30 mm/kasan/common.c:52 kasan_save_free_info+0x2e/0x40 mm/kasan/generic.c:521 ____kasan_slab_free mm/kasan/common.c:236 [inline] ____kasan_slab_free+0x160/0x1c0 mm/kasan/common.c:200 kasan_slab_free include/linux/kasan.h:162 [inline] slab_free_hook mm/slub.c:1781 [inline] slab_free_freelist_hook+0x8b/0x1c0 mm/slub.c:1807 slab_free mm/slub.c:3787 [inline] __kmem_cache_free+0xaf/0x2d0 mm/slub.c:3800 skb_kfree_head net/core/skbuff.c:858 [inline] skb_free_head+0x108/0x1a0 net/core/skbuff.c:870 skb_release_data+0x57a/0x820 net/core/skbuff.c:899 skb_release_all net/core/skbuff.c:964 [inline] __kfree_skb net/core/skbuff.c:978 [inline] kfree_skb_reason+0x179/0x3a0 net/core/skbuff.c:1011 kfree_skb include/linux/skbuff.h:1225 [inline] j1939_session_skb_drop_old net/can/j1939/transport.c:347 [inline] j1939_xtp_rx_cts_one net/can/j1939/transport.c:1445 [inline] j1939_xtp_rx_cts+0x614/0xfa0 net/can/j1939/transport.c:1484 j1939_tp_cmd_recv net/can/j1939/transport.c:2072 [inline] j1939_tp_recv+0x565/0xf50 net/can/j1939/transport.c:2144 j1939_can_recv net/can/j1939/main.c:112 [inline] j1939_can_recv+0x78e/0xa80 net/can/j1939/main.c:38 deliver net/can/af_can.c:572 [inline] can_rcv_filter+0x5d4/0x8d0 net/can/af_can.c:606 can_receive+0x31d/0x5c0 net/can/af_can.c:663 can_rcv+0x1e1/0x280 net/can/af_can.c:687 __netif_receive_skb_one_core+0x114/0x180 net/core/dev.c:5479 __netif_receive_skb+0x1f/0x1c0 net/core/dev.c:5593 process_backlog+0x239/0x800 net/core/dev.c:5921 __napi_poll+0xb7/0x6f0 net/core/dev.c:6482 napi_poll net/core/dev.c:6549 [inline] net_rx_action+0x9c2/0xd80 net/core/dev.c:6659 __do_softirq+0x1d4/0x905 kernel/softirq.c:571 The buggy address belongs to the object at ffff88807a46e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 3776 bytes inside of freed 4096-byte region [ffff88807a46e000, ffff88807a46f000) The buggy address belongs to the physical page: page:ffffea0001e91a00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x7a468 head:ffffea0001e91a00 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff) raw: 00fff00000010200 ffff888012442140 dead000000000100 dead000000000122 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5456, tgid 5455 (syz-executor.4), ts 84011200239, free_ts 83950779102 prep_new_page mm/page_alloc.c:2553 [inline] get_page_from_freelist+0x1190/0x2e20 mm/page_alloc.c:4326 __alloc_pages+0x1cb/0x4a0 mm/page_alloc.c:5592 alloc_pages+0x1aa/0x270 mm/mempolicy.c:2283 alloc_slab_page mm/slub.c:1851 [inline] allocate_slab+0x25f/0x390 mm/slub.c:1998 new_slab mm/slub.c:2051 [inline] ___slab_alloc+0xa91/0x1400 mm/slub.c:3193 __slab_alloc.constprop.0+0x56/0xa0 mm/slub.c:3292 __slab_alloc_node mm/slub.c:3345 [inline] slab_alloc_node mm/slub.c:3442 [inline] __kmem_cache_alloc_node+0x136/0x320 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:966 [inline] __kmalloc_node_track_caller+0x4f/0x1a0 mm/slab_common.c:987 kmalloc_reserve+0xf0/0x270 net/core/skbuff.c:537 __alloc_skb+0x129/0x330 net/core/skbuff.c:606 alloc_skb include/linux/skbuff.h:1277 [inline] alloc_skb_with_frags+0x97/0x6c0 net/core/skbuff.c:6318 sock_alloc_send_pskb+0x7a7/0x930 net/core/sock.c:2734 sock_alloc_send_skb include/net/sock.h:1860 [inline] j1939_sk_alloc_skb net/can/j1939/socket.c:864 [inline] j1939_sk_send_loop net/can/j1939/socket.c:1121 [inline] j1939_sk_sendmsg+0x6ba/0x13a0 net/can/j1939/socket.c:1256 sock_sendmsg_nosec net/socket.c:724 [inline] sock_sendmsg+0xde/0x190 net/socket.c:747 sock_no_sendpage+0x10c/0x160 net/core/sock.c:3235 kernel_sendpage.part.0+0x1d5/0x700 net/socket.c:3580 page last free stack trace: reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1454 [inline] free_pcp_prepare+0x5d5/0xa50 mm/page_alloc.c:1504 free_unref_page_prepare mm/page_alloc.c:3388 [inline] free_unref_page+0x1d/0x490 mm/page_alloc.c:3483 __unfreeze_partials+0x17c/0x1a0 mm/slub.c:2637 qlink_free mm/kasan/quarantine.c:168 [inline] qlist_free_all+0x6a/0x170 mm/kasan/quarantine.c:187 kasan_quarantine_reduce+0x192/0x220 mm/kasan/quarantine.c:294 __kasan_slab_alloc+0x63/0x90 mm/kasan/common.c:305 kasan_slab_alloc include/linux/kasan.h:186 [inline] slab_post_alloc_hook mm/slab.h:769 [inline] slab_alloc_node mm/slub.c:3452 [inline] slab_alloc mm/slub.c:3460 [inline] __kmem_cache_alloc_lru mm/slub.c:3467 [inline] kmem_cache_alloc+0x17c/0x3b0 mm/slub.c:3476 getname_flags.part.0+0x50/0x4f0 fs/namei.c:140 getname_flags+0x9e/0xe0 include/linux/audit.h:321 user_path_at_empty+0x2f/0x60 fs/namei.c:2876 do_readlinkat+0xcd/0x2f0 fs/stat.c:477 __do_sys_readlink fs/stat.c:510 [inline] __se_sys_readlink fs/stat.c:507 [inline] __x64_sys_readlink+0x78/0xb0 fs/stat.c:507 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Memory state around the buggy address: ffff88807a46ed80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a46ee00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff88807a46ee80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff88807a46ef00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff88807a46ef80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ==================================================================