ci starts bisection 2023-03-04 07:58:09.033433455 +0000 UTC m=+251015.404686307
bisecting fixing commit since 1d41d2e82623b40ee27811fe9ea38bafe2e722e9
building syzkaller on 8b9ca619df135211a89cc19719f2705d0016045d
ensuring issue is reproducible on original commit 1d41d2e82623b40ee27811fe9ea38bafe2e722e9

testing commit 1d41d2e82623b40ee27811fe9ea38bafe2e722e9 gcc
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 768f23e5cc109a318fc7efa332ea01322ce17215036c3f09b38891ee78e9a2db
all runs: crashed: WARNING in j1939_session_deactivate
testing current HEAD 0988a0ea791999ebbf95693f2676381825b05033
testing commit 0988a0ea791999ebbf95693f2676381825b05033 gcc
compiler: gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
kernel signature: 0e052d2b1c26b5f4a67d66b60af541a9f124d595e4c209241e7e6c1181f93cef
run #0: crashed: KASAN: slab-use-after-free Read in skb_release_data
run #1: OK
run #2: OK
run #3: OK
run #4: OK
run #5: OK
run #6: OK
run #7: OK
run #8: OK
run #9: OK
reproducer seems to be flaky
Reproducer flagged being flaky
revisions tested: 2, total time: 30m38.47593557s (build: 15m14.36002735s, test: 14m33.814813568s)
the crash still happens on HEAD
commit msg: Merge tag 'for-v6.3-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply
crash: KASAN: slab-use-after-free Read in skb_release_data
vcan0: j1939_tp_rxtimer: 0xffff88806b89bc00: rx timeout, send abort
vcan0: j1939_tp_rxtimer: 0xffff88806ab8b400: rx timeout, send abort
vcan0: j1939_tp_rxtimer: 0xffff88801beca400: abort rx timeout. Force session deactivation
==================================================================
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+0x52a/0x650 net/core/skbuff.c:886
Read of size 1 at addr ffff88806b920ec0 by task ksoftirqd/0/15

CPU: 0 PID: 15 Comm: ksoftirqd/0 Not tainted 6.2.0-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/16/2023
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0x64/0xb0 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+0x52a/0x650 net/core/skbuff.c:886
 skb_release_all net/core/skbuff.c:966 [inline]
 __kfree_skb net/core/skbuff.c:980 [inline]
 consume_skb net/core/skbuff.c:1193 [inline]
 consume_skb+0xa6/0x100 net/core/skbuff.c:1187
 j1939_xtp_rx_dat_one+0x74a/0xf90 net/can/j1939/transport.c:1907
 j1939_xtp_rx_dat net/can/j1939/transport.c:1933 [inline]
 j1939_tp_recv+0x636/0xc10 net/can/j1939/transport.c:2127
 j1939_can_recv net/can/j1939/main.c:112 [inline]
 j1939_can_recv+0x60f/0x8a0 net/can/j1939/main.c:38
 deliver net/can/af_can.c:572 [inline]
 can_rcv_filter+0x4ce/0x7b0 net/can/af_can.c:606
 can_receive+0x2ae/0x4b0 net/can/af_can.c:663
 can_rcv+0x15e/0x220 net/can/af_can.c:687
 __netif_receive_skb_one_core+0x104/0x180 net/core/dev.c:5479
 process_backlog+0x1fe/0x750 net/core/dev.c:5921
 __napi_poll+0x9e/0x690 net/core/dev.c:6482
 napi_poll net/core/dev.c:6549 [inline]
 net_rx_action+0x8c5/0xcb0 net/core/dev.c:6659
 __do_softirq+0x2e3/0xae3 kernel/softirq.c:571
 run_ksoftirqd kernel/softirq.c:934 [inline]
 run_ksoftirqd+0x31/0x60 kernel/softirq.c:926
 smpboot_thread_fn+0x55c/0x910 kernel/smpboot.c:164
 kthread+0x298/0x340 kernel/kthread.c:376
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308
 </TASK>

Allocated by task 6562:
 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+0x5b/0xc0 mm/slab_common.c:987
 kmalloc_reserve+0xbf/0x1d0 net/core/skbuff.c:539
 __alloc_skb+0xd8/0x280 net/core/skbuff.c:608
 alloc_skb include/linux/skbuff.h:1277 [inline]
 alloc_skb_with_frags+0x77/0x610 net/core/skbuff.c:6303
 sock_alloc_send_pskb+0x639/0x7c0 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+0x5ac/0x10e0 net/can/j1939/socket.c:1256
 sock_sendmsg_nosec net/socket.c:722 [inline]
 sock_sendmsg+0xc0/0x150 net/socket.c:745
 sock_no_sendpage+0x100/0x150 net/core/sock.c:3234
 kernel_sendpage.part.0+0x12f/0x520 net/socket.c:3583
 kernel_sendpage net/socket.c:3580 [inline]
 sock_sendpage+0xc5/0x1d0 net/socket.c:1078
 pipe_to_sendpage+0x249/0x410 fs/splice.c:454
 splice_from_pipe_feed fs/splice.c:508 [inline]
 __splice_from_pipe+0x379/0x830 fs/splice.c:652
 splice_from_pipe fs/splice.c:687 [inline]
 generic_splice_sendpage+0xbe/0x120 fs/splice.c:835
 do_splice_from fs/splice.c:856 [inline]
 direct_splice_actor+0xff/0x1d0 fs/splice.c:1023
 splice_direct_to_actor+0x2bf/0x790 fs/splice.c:978
 do_splice_direct+0x14c/0x260 fs/splice.c:1066
 do_sendfile+0x93d/0x1170 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+0x18a/0x1d0 fs/read_write.c:1309
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0x80 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_release_data+0x400/0x650 net/core/skbuff.c:901
 skb_release_all net/core/skbuff.c:966 [inline]
 __kfree_skb net/core/skbuff.c:980 [inline]
 kfree_skb_reason+0x12a/0x380 net/core/skbuff.c:1013
 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:1438 [inline]
 j1939_xtp_rx_cts+0x5ea/0x1080 net/can/j1939/transport.c:1477
 j1939_tp_cmd_recv net/can/j1939/transport.c:2065 [inline]
 j1939_tp_recv+0x46f/0xc10 net/can/j1939/transport.c:2137
 j1939_can_recv net/can/j1939/main.c:112 [inline]
 j1939_can_recv+0x60f/0x8a0 net/can/j1939/main.c:38
 deliver net/can/af_can.c:572 [inline]
 can_rcv_filter+0x4ce/0x7b0 net/can/af_can.c:606
 can_receive+0x2ae/0x4b0 net/can/af_can.c:663
 can_rcv+0x15e/0x220 net/can/af_can.c:687
 __netif_receive_skb_one_core+0x104/0x180 net/core/dev.c:5479
 process_backlog+0x1fe/0x750 net/core/dev.c:5921
 __napi_poll+0x9e/0x690 net/core/dev.c:6482
 napi_poll net/core/dev.c:6549 [inline]
 net_rx_action+0x8c5/0xcb0 net/core/dev.c:6659
 __do_softirq+0x2e3/0xae3 kernel/softirq.c:571

The buggy address belongs to the object at ffff88806b920000
 which belongs to the cache kmalloc-4k of size 4096
The buggy address is located 3776 bytes inside of
 freed 4096-byte region [ffff88806b920000, ffff88806b921000)

The buggy address belongs to the physical page:
page:ffffea0001ae4800 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x6b920
head:ffffea0001ae4800 order:3 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 ffff888010442140 dead000000000122 0000000000000000
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 6562, tgid 6559 (syz-executor.3), ts 218067827872, free_ts 200134006457
 prep_new_page mm/page_alloc.c:2552 [inline]
 get_page_from_freelist+0x1190/0x2f80 mm/page_alloc.c:4325
 __alloc_pages+0x1cb/0x5c0 mm/page_alloc.c:5591
 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+0x136/0x330 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:966 [inline]
 __kmalloc_node_track_caller+0x4b/0xc0 mm/slab_common.c:987
 kmalloc_reserve+0xbf/0x1d0 net/core/skbuff.c:539
 __alloc_skb+0xd8/0x280 net/core/skbuff.c:608
 alloc_skb include/linux/skbuff.h:1277 [inline]
 alloc_skb_with_frags+0x77/0x610 net/core/skbuff.c:6303
 sock_alloc_send_pskb+0x639/0x7c0 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+0x5ac/0x10e0 net/can/j1939/socket.c:1256
 sock_sendmsg_nosec net/socket.c:722 [inline]
 sock_sendmsg+0xc0/0x150 net/socket.c:745
 sock_no_sendpage+0x100/0x150 net/core/sock.c:3234
 kernel_sendpage.part.0+0x12f/0x520 net/socket.c:3583
 kernel_sendpage net/socket.c:3580 [inline]
 sock_sendpage+0xc5/0x1d0 net/socket.c:1078
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1453 [inline]
 free_pcp_prepare+0x65a/0xb40 mm/page_alloc.c:1503
 free_unref_page_prepare mm/page_alloc.c:3387 [inline]
 free_unref_page+0x1d/0x490 mm/page_alloc.c:3482
 __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+0x175/0x320 mm/slub.c:3476
 getname_flags.part.0+0x4a/0x440 fs/namei.c:140
 user_path_at_empty+0x22/0x50 fs/namei.c:2876
 do_readlinkat+0xa9/0x270 fs/stat.c:477
 __do_sys_readlink fs/stat.c:510 [inline]
 __se_sys_readlink fs/stat.c:507 [inline]
 __x64_sys_readlink+0x73/0xb0 fs/stat.c:507
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0x80 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Memory state around the buggy address:
 ffff88806b920d80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806b920e00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff88806b920e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                           ^
 ffff88806b920f00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88806b920f80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================