On Fri, May 31, 2019 at 10:59 PM syzbot <syzbot+7f3b6b106be8dcdcd...@syzkaller.appspotmail.com> wrote: > > Hello, > > syzbot found the following crash on: > > HEAD commit: bec7550c Merge tag 'docs-5.2-fixes2' of git://git.lwn.net/.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=152a0916a00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=64479170dcaf0e11 > dashboard link: https://syzkaller.appspot.com/bug?extid=7f3b6b106be8dcdcdeec > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=1142cd4ca00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=10f81d72a00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+7f3b6b106be8dcdcd...@syzkaller.appspotmail.com > > executing program > executing program > executing program > executing program > executing program > BUG: memory leak > unreferenced object 0xffff8881114f5d80 (size 96): > comm "syz-executor934", pid 7160, jiffies 4294993058 (age 31.950s) > hex dump (first 32 bytes): > 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 00 ................ > backtrace: > [<00000000ce7a1326>] kmemleak_alloc_recursive > include/linux/kmemleak.h:55 [inline] > [<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline] > [<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline] > [<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline] > [<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0 > net/sctp/stream.c:157 > [<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00 > net/sctp/socket.c:1882
is this possible to be a false positive? As in my testing, I tracked the objects allocated by "sctp_sendmsg_to_asoc () -> sctp_stream_init_ext()." all of them got freed properly in sctp_stream_free(), while this warning was still triggered. > [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102 > [<0000000094bdc32e>] inet_sendmsg+0x64/0x120 net/ipv4/af_inet.c:802 > [<0000000022d1c2a5>] sock_sendmsg_nosec net/socket.c:652 [inline] > [<0000000022d1c2a5>] sock_sendmsg+0x54/0x70 net/socket.c:671 > [<000000006ab53119>] sock_write_iter+0xb6/0x130 net/socket.c:1000 > [<00000000973772ef>] call_write_iter include/linux/fs.h:1872 [inline] > [<00000000973772ef>] new_sync_write+0x1ad/0x260 fs/read_write.c:483 > [<0000000033f2491b>] __vfs_write+0x87/0xa0 fs/read_write.c:496 > [<00000000372fbd56>] vfs_write fs/read_write.c:558 [inline] > [<00000000372fbd56>] vfs_write+0xee/0x210 fs/read_write.c:542 > [<000000007ccb2ea5>] ksys_write+0x7c/0x130 fs/read_write.c:611 > [<000000001c29b8c7>] __do_sys_write fs/read_write.c:623 [inline] > [<000000001c29b8c7>] __se_sys_write fs/read_write.c:620 [inline] > [<000000001c29b8c7>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620 > [<0000000014d9243b>] do_syscall_64+0x76/0x1a0 > arch/x86/entry/common.c:301 > [<0000000059f6e9a8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > BUG: memory leak > unreferenced object 0xffff8881114f5d80 (size 96): > comm "syz-executor934", pid 7160, jiffies 4294993058 (age 33.160s) > hex dump (first 32 bytes): > 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 00 ................ > backtrace: > [<00000000ce7a1326>] kmemleak_alloc_recursive > include/linux/kmemleak.h:55 [inline] > [<00000000ce7a1326>] slab_post_alloc_hook mm/slab.h:439 [inline] > [<00000000ce7a1326>] slab_alloc mm/slab.c:3326 [inline] > [<00000000ce7a1326>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553 > [<000000007abb7ac9>] kmalloc include/linux/slab.h:547 [inline] > [<000000007abb7ac9>] kzalloc include/linux/slab.h:742 [inline] > [<000000007abb7ac9>] sctp_stream_init_ext+0x2b/0xa0 > net/sctp/stream.c:157 > [<0000000048ecb9c1>] sctp_sendmsg_to_asoc+0x946/0xa00 > net/sctp/socket.c:1882 > [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102 > [<0000000094bdc32e>] inet_sendmsg+0x64/0x120 net/ipv4/af_inet.c:802 > [<0000000022d1c2a5>] sock_sendmsg_nosec net/socket.c:652 [inline] > [<0000000022d1c2a5>] sock_sendmsg+0x54/0x70 net/socket.c:671 > [<000000006ab53119>] sock_write_iter+0xb6/0x130 net/socket.c:1000 > [<00000000973772ef>] call_write_iter include/linux/fs.h:1872 [inline] > [<00000000973772ef>] new_sync_write+0x1ad/0x260 fs/read_write.c:483 > [<0000000033f2491b>] __vfs_write+0x87/0xa0 fs/read_write.c:496 > [<00000000372fbd56>] vfs_write fs/read_write.c:558 [inline] > [<00000000372fbd56>] vfs_write+0xee/0x210 fs/read_write.c:542 > [<000000007ccb2ea5>] ksys_write+0x7c/0x130 fs/read_write.c:611 > [<000000001c29b8c7>] __do_sys_write fs/read_write.c:623 [inline] > [<000000001c29b8c7>] __se_sys_write fs/read_write.c:620 [inline] > [<000000001c29b8c7>] __x64_sys_write+0x1e/0x30 fs/read_write.c:620 > [<0000000014d9243b>] do_syscall_64+0x76/0x1a0 > arch/x86/entry/common.c:301 > [<0000000059f6e9a8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > executing program > executing program > executing program > executing program > executing program > executing program > > > --- > This bug is generated by a bot. It may contain errors. > See https://goo.gl/tpsmEJ for more information about syzbot. > syzbot engineers can be reached at syzkal...@googlegroups.com. > > syzbot will keep track of this bug report. See: > https://goo.gl/tpsmEJ#status for how to communicate with syzbot. > syzbot can test patches for this bug, for details see: > https://goo.gl/tpsmEJ#testing-patches
