Re: [syzbot] [can?] memory leak in j1939_netdev_start

[syzbot]

Hello,

syzbot has tested the proposed patch but the reproducer is still triggering an issue:
memory leak in corrupted

BUG: memory leak
unreferenced object 0xffff88810e94a000 (size 8192):
  comm "syz-executor.4", pid 5915, jiffies 4294946150
  hex dump (first 32 bytes):
    00 a0 94 0e 81 88 ff ff 00 a0 94 0e 81 88 ff ff  ................
    00 00 00 00 00 00 00 00 00 00 70 10 81 88 ff ff  ..........p.....
  backtrace (crc 77c14305):
    [<ffffffff815fa713>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
    [<ffffffff815fa713>] slab_post_alloc_hook mm/slub.c:3817 [inline]
    [<ffffffff815fa713>] slab_alloc_node mm/slub.c:3860 [inline]
    [<ffffffff815fa713>] kmalloc_trace+0x283/0x330 mm/slub.c:4007
    [<ffffffff845842c9>] kmalloc include/linux/slab.h:590 [inline]
    [<ffffffff845842c9>] kzalloc include/linux/slab.h:711 [inline]
    [<ffffffff845842c9>] j1939_priv_create net/can/j1939/main.c:135 [inline]
    [<ffffffff845842c9>] j1939_netdev_start+0x159/0x6f0 net/can/j1939/main.c:272
    [<ffffffff84585f2e>] j1939_sk_bind+0x21e/0x550 net/can/j1939/socket.c:486
    [<ffffffff83f04a8c>] __sys_bind+0x11c/0x130 net/socket.c:1847
    [<ffffffff83f04abc>] __do_sys_bind net/socket.c:1858 [inline]
    [<ffffffff83f04abc>] __se_sys_bind net/socket.c:1856 [inline]
    [<ffffffff83f04abc>] __x64_sys_bind+0x1c/0x20 net/socket.c:1856
    [<ffffffff84bc08c0>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    [<ffffffff84bc08c0>] do_syscall_64+0x50/0x140 arch/x86/entry/common.c:83
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b

BUG: memory leak
unreferenced object 0xffff888122f26000 (size 8192):
  comm "syz-executor.1", pid 5923, jiffies 4294946164
  hex dump (first 32 bytes):
    00 60 f2 22 81 88 ff ff 00 60 f2 22 81 88 ff ff  .`.".....`."....
    00 00 00 00 00 00 00 00 00 80 60 10 81 88 ff ff  ..........`.....
  backtrace (crc c2cb0355):
    [<ffffffff815fa713>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
    [<ffffffff815fa713>] slab_post_alloc_hook mm/slub.c:3817 [inline]
    [<ffffffff815fa713>] slab_alloc_node mm/slub.c:3860 [inline]
    [<ffffffff815fa713>] kmalloc_trace+0x283/0x330 mm/slub.c:4007
    [<ffffffff845842c9>] kmalloc include/linux/slab.h:590 [inline]
    [<ffffffff845842c9>] kzalloc include/linux/slab.h:711 [inline]
    [<ffffffff845842c9>] j1939_priv_create net/can/j1939/main.c:135 [inline]
    [<ffffffff845842c9>] j1939_netdev_start+0x159/0x6f0 net/can/j1939/main.c:272
    [<ffffffff84585f2e>] j1939_sk_bind+0x21e/0x550 net/can/j1939/socket.c:486
    [<ffffffff83f04a8c>] __sys_bind+0x11c/0x130 net/socket.c:1847
    [<ffffffff83f04abc>] __do_sys_bind net/socket.c:1858 [inline]
    [<ffffffff83f04abc>] __se_sys_bind net/socket.c:1856 [inline]
    [<ffffffff83f04abc>] __x64_sys_bind+0x1c/0x20 net/socket.c:1856
    [<ffffffff84bc08c0>] do_syscall_x64 arch/x86/entry/common.c:52 [inline]
    [<ffffffff84bc08c0>] do_syscall_64+0x50/0x140 arch/x86/entry/common.c:83
    [<ffffffff84c0008b>] entry_SYSCALL_64_after_hwframe+0x63/0x6b

BUG: memory leak
unreferenced object 0xffff888122c06700 (size 240):
  comm "softirq", pid 0, jiffies 4294946164
  hex dump (first 32 bytes):
    68 42 2f 22 81 88 ff ff 68 42 2f 22 81 88 ff ff  hB/"....hB/"....
    00 80 60 10 81 88 ff ff 00 00 00 00 00 00 00 00  ..`.............
  backtrace (crc 205e59a3):
    [<ffffffff815f9bba>] kmemleak_alloc_recursive include/linux/kmemleak.h:42 [inline]
    [<ffffffff815f9bba>] slab_post_alloc_hook mm/slub.c:3817 [inline]
    [<ffffffff815f9bba>] slab_alloc_node mm/slub.c:3860 [inline]
    [<ffffffff815f9bba>] kmem_cache_alloc_node+0x28a/0x330 mm/slub.c:3903
    [<ffffffff83f1844f>] __alloc_skb+0x1ef/0x230 net/core/skbuff.c:641
    [<ffffffff8458ceea>] alloc_skb include/linux/skbuff.h:1296 [inline]
    [<ffffffff8458ceea>] j1939_session_fresh_new net/can/j1939/transport.c:1536 [inline]
    [<ffffffff8458ceea>] j1939_xtp_rx_rts_session_new net/can/j1939/transport.c:1634 [inline]
    [<ffffffff8458ceea>] j1939_xtp_rx_rts+0x4ba/0xa70 net/can/j1939/transport.c:1738
    [<ffffffff8458d9d5>] j1939_tp_cmd_recv net/can/j1939/transport.c:2063 [inline]
    [<ffffffff8458d9d5>] j1939_tp_recv+0x1b5/0x7f0 net/can/j1939/transport.c:2150
    [<ffffffff84583e99>] j1939_can_recv+0x349/0x4e0 net/can/j1939/main.c:112
    [<ffffffff845748e4>] deliver net/can/af_can.c:572 [inline]
    [<ffffffff845748e4>] can_rcv_filter+0xd4/0x290 net/can/af_can.c:606
    [<ffffffff84574fa0>] can_receive+0xf0/0x140 net/can/af_can.c:663
    [<ffffffff845750e0>] can_rcv+0xf0/0x130 net/can/af_can.c:687
    [<ffffffff83f50e66>] __netif_receive_skb_one_core+0x66/0x90 net/core/dev.c:5534
    [<ffffffff83f50edd>] __netif_receive_skb+0x1d/0x90 net/core/dev.c:5648
    [<ffffffff83f5123c>] process_backlog+0xbc/0x190 net/core/dev.c:5976
    [<ffffffff83f523ce>] __napi_poll+0x3e/0x310 net/core/dev.c:6576
    [<ffffffff83f52de8>] napi_poll net/core/dev.c:6645 [inline]
    [<ffffffff83f52de8>] net_rx_action+0x3d8/0x510 net/core/dev.c:6778
    [<ffffffff84bde94d>] __do_softirq+0xbd/0x2b0 kernel/softirq.c:553

BUG: memory leak
unreferenced object 0xffff8881231e0000 (size 131072):
  comm "softirq", pid 0, jiffies 4294946164
  hex dump (first 32 bytes):
    0e 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace (crc f7abe560):
    [<ffffffff815f315e>] __kmalloc_large_node+0xde/0x150 mm/slub.c:3935
    [<ffffffff815f8faf>] __do_kmalloc_node mm/slub.c:3969 [inline]
    [<ffffffff815f8faf>] __kmalloc_node_track_caller+0x35f/0x420 mm/slub.c:4001
    [<ffffffff83f146a6>] kmalloc_reserve+0x96/0x170 net/core/skbuff.c:582
    [<ffffffff83f18335>] __alloc_skb+0xd5/0x230 net/core/skbuff.c:651
    [<ffffffff8458ceea>] alloc_skb include/linux/skbuff.h:1296 [inline]
    [<ffffffff8458ceea>] j1939_session_fresh_new net/can/j1939/transport.c:1536 [inline]
    [<ffffffff8458ceea>] j1939_xtp_rx_rts_session_new net/can/j1939/transport.c:1634 [inline]
    [<ffffffff8458ceea>] j1939_xtp_rx_rts+0x4ba/0xa70 net/can/j1939/transport.c:1738
    [<ffffffff8458d9d5>] j1939_tp_cmd_recv net/can/j1939/transport.c:2063 [inline]
    [<ffffffff8458d9d5>] j1939_tp_recv+0x1b5/0x7f0 net/can/j1939/transport.c:2150
    [<ffffffff84583e99>] j1939_can_recv+0x349/0x4e0 net/can/j1939/main.c:112
    [<ffffffff845748e4>] deliver net/can/af_can.c:572 [inline]
    [<ffffffff845748e4>] can_rcv_filter+0xd4/0x290 net/can/af_can.c:606
    [<ffffffff84574fa0>] can_receive+0xf0/0x140 net/can/af_can.c:663
    [<ffffffff845750e0>] can_rcv+0xf0/0x130 net/can/af_can.c:687
    [<ffffffff83f50e66>] __netif_receive_skb_one_core+0x66/0x90 net/core/dev.c:5534
    [<ffffffff83f50edd>] __netif_receive_skb+0x1d/0x90 net/core/dev.c:5648
    [<ffffffff83f5123c>] process_backlog+0xbc/0x190 net/core/dev.c:5976
    [<ffffffff83f523ce>] __napi_poll+0x3e/0x310 net/core/dev.c:6576
    [<ffffffff83f52de8>] napi_poll net/core/dev.c:6645 [inline]
    [<ffffffff83f52de8>] net_rx_action+0x3d8/0x510 net/core/dev.c:6778
    [<ffffffff84bde94d>] __do_softirq+0xbd/0x2b0 kernel/softirq.c:553



Tested on:

commit:         615d3006 Merge tag 'trace-v6.8-rc1' of git://git.kerne..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
console output: https://syzkaller.appspot.com/x/log.txt?x=100e8b3be80000
kernel config:  https://syzkaller.appspot.com/x/.config?x=9f6b64adeddd3dbc
dashboard link: https://syzkaller.appspot.com/bug?extid=1d37bef05da87b99c5a6
compiler:       gcc (Debian 12.2.0-14) 12.2.0, GNU ld (GNU Binutils for Debian) 2.40
patch:          https://syzkaller.appspot.com/x/patch.diff?x=17d2a6f7e80000