Re: memory leak in sctp_stream_init_ext
From: Dmitry Vyukov <dvyukov@google.com>
Date: 2019-06-04 13:39:11
Also in:
linux-sctp, lkml
On Tue, Jun 4, 2019 at 3:37 PM Xin Long [off-list ref] wrote:
On Fri, May 31, 2019 at 10:59 PM syzbot [off-list ref] wrote:quoted
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+7f3b6b106be8dcdcdeec@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:1882is this possible to be a false positive?
https://goo.gl/tpsmEJ#memory-leaks
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.quoted
[<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 syzkaller@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-- You received this message because you are subscribed to the Google Groups "syzkaller-bugs" group. To unsubscribe from this group and stop receiving emails from it, send an email to syzkaller-bugs+unsubscribe@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/syzkaller-bugs/CADvbK_evGyJZaUQZa6U26tJSQCNW4jb3uqLWGQGF_7HJgv-Sog%40mail.gmail.com. For more options, visit https://groups.google.com/d/optout.