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* memory leak in sctp_stream_init_ext
@ 2019-05-31 14:58 syzbot
  2019-06-04 13:36 ` Xin Long
  0 siblings, 1 reply; 7+ messages in thread
From: syzbot @ 2019-05-31 14:58 UTC (permalink / raw)
  To: davem, linux-kernel, linux-sctp, marcelo.leitner, netdev,
	nhorman, syzkaller-bugs, vyasevich

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: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

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

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: memory leak in sctp_stream_init_ext
  2019-05-31 14:58 memory leak in sctp_stream_init_ext syzbot
@ 2019-06-04 13:36 ` Xin Long
  2019-06-04 13:38   ` Dmitry Vyukov
  0 siblings, 1 reply; 7+ messages in thread
From: Xin Long @ 2019-06-04 13:36 UTC (permalink / raw)
  To: syzbot
  Cc: davem, LKML, linux-sctp, Marcelo Ricardo Leitner, network dev,
	Neil Horman, syzkaller-bugs, Vlad Yasevich

On Fri, May 31, 2019 at 10:59 PM syzbot
<syzbot+7f3b6b106be8dcdcdeec@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+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: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 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

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: memory leak in sctp_stream_init_ext
  2019-06-04 13:36 ` Xin Long
@ 2019-06-04 13:38   ` Dmitry Vyukov
  2019-10-04  6:50     ` [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Eric Biggers
  0 siblings, 1 reply; 7+ messages in thread
From: Dmitry Vyukov @ 2019-06-04 13:38 UTC (permalink / raw)
  To: Xin Long
  Cc: syzbot, davem, LKML, linux-sctp, Marcelo Ricardo Leitner,
	network dev, Neil Horman, syzkaller-bugs, Vlad Yasevich

On Tue, Jun 4, 2019 at 3:37 PM Xin Long <lucien.xin@gmail.com> wrote:
>
> On Fri, May 31, 2019 at 10:59 PM syzbot
> <syzbot+7f3b6b106be8dcdcdeec@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+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:1882
>
> is 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.
>
> >      [<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.

^ permalink raw reply	[flat|nested] 7+ messages in thread

* [PATCH] lib/generic-radix-tree.c: add kmemleak annotations
  2019-06-04 13:38   ` Dmitry Vyukov
@ 2019-10-04  6:50     ` Eric Biggers
  2019-10-04 12:21       ` Marcelo Ricardo Leitner
                         ` (2 more replies)
  0 siblings, 3 replies; 7+ messages in thread
From: Eric Biggers @ 2019-10-04  6:50 UTC (permalink / raw)
  To: Andrew Morton
  Cc: linux-mm, linux-sctp, linux-kernel, syzkaller-bugs,
	Catalin Marinas, Kent Overstreet, Vlad Yasevich, Xin Long,
	Neil Horman, Marcelo Ricardo Leitner

From: Eric Biggers <ebiggers@google.com>

Kmemleak is falsely reporting a leak of the slab allocation in
sctp_stream_init_ext():

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
     [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
     [...]

But it's freed later.  Kmemleak misses the allocation because its
pointer is stored in the generic radix tree sctp_stream::out, and the
generic radix tree uses raw pages which aren't tracked by kmemleak.

Fix this by adding the kmemleak hooks to the generic radix tree code.

Reported-by: syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com
Signed-off-by: Eric Biggers <ebiggers@google.com>
---
 lib/generic-radix-tree.c | 32 ++++++++++++++++++++++++++------
 1 file changed, 26 insertions(+), 6 deletions(-)

diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c
index ae25e2fa2187..f25eb111c051 100644
--- a/lib/generic-radix-tree.c
+++ b/lib/generic-radix-tree.c
@@ -2,6 +2,7 @@
 #include <linux/export.h>
 #include <linux/generic-radix-tree.h>
 #include <linux/gfp.h>
+#include <linux/kmemleak.h>
 
 #define GENRADIX_ARY		(PAGE_SIZE / sizeof(struct genradix_node *))
 #define GENRADIX_ARY_SHIFT	ilog2(GENRADIX_ARY)
@@ -75,6 +76,27 @@ void *__genradix_ptr(struct __genradix *radix, size_t offset)
 }
 EXPORT_SYMBOL(__genradix_ptr);
 
+static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask)
+{
+	struct genradix_node *node;
+
+	node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO);
+
+	/*
+	 * We're using pages (not slab allocations) directly for kernel data
+	 * structures, so we need to explicitly inform kmemleak of them in order
+	 * to avoid false positive memory leak reports.
+	 */
+	kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask);
+	return node;
+}
+
+static inline void genradix_free_node(struct genradix_node *node)
+{
+	kmemleak_free(node);
+	free_page((unsigned long)node);
+}
+
 /*
  * Returns pointer to the specified byte @offset within @radix, allocating it if
  * necessary - newly allocated slots are always zeroed out:
@@ -97,8 +119,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
 			break;
 
 		if (!new_node) {
-			new_node = (void *)
-				__get_free_page(gfp_mask|__GFP_ZERO);
+			new_node = genradix_alloc_node(gfp_mask);
 			if (!new_node)
 				return NULL;
 		}
@@ -121,8 +142,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
 		n = READ_ONCE(*p);
 		if (!n) {
 			if (!new_node) {
-				new_node = (void *)
-					__get_free_page(gfp_mask|__GFP_ZERO);
+				new_node = genradix_alloc_node(gfp_mask);
 				if (!new_node)
 					return NULL;
 			}
@@ -133,7 +153,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
 	}
 
 	if (new_node)
-		free_page((unsigned long) new_node);
+		genradix_free_node(new_node);
 
 	return &n->data[offset];
 }
@@ -191,7 +211,7 @@ static void genradix_free_recurse(struct genradix_node *n, unsigned level)
 				genradix_free_recurse(n->children[i], level - 1);
 	}
 
-	free_page((unsigned long) n);
+	genradix_free_node(n);
 }
 
 int __genradix_prealloc(struct __genradix *radix, size_t size,
-- 
2.23.0


^ permalink raw reply related	[flat|nested] 7+ messages in thread

* Re: [PATCH] lib/generic-radix-tree.c: add kmemleak annotations
  2019-10-04  6:50     ` [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Eric Biggers
@ 2019-10-04 12:21       ` Marcelo Ricardo Leitner
  2019-10-04 12:27       ` Neil Horman
  2019-10-04 14:48       ` Catalin Marinas
  2 siblings, 0 replies; 7+ messages in thread
From: Marcelo Ricardo Leitner @ 2019-10-04 12:21 UTC (permalink / raw)
  To: Eric Biggers
  Cc: Andrew Morton, linux-mm, linux-sctp, linux-kernel,
	syzkaller-bugs, Catalin Marinas, Kent Overstreet, Vlad Yasevich,
	Xin Long, Neil Horman

On Thu, Oct 03, 2019 at 11:50:39PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Kmemleak is falsely reporting a leak of the slab allocation in
> sctp_stream_init_ext():
> 
> 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
>      [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
>      [...]
> 
> But it's freed later.  Kmemleak misses the allocation because its
> pointer is stored in the generic radix tree sctp_stream::out, and the
> generic radix tree uses raw pages which aren't tracked by kmemleak.
> 
> Fix this by adding the kmemleak hooks to the generic radix tree code.

Nice, thanks Eric.

Reviewed-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>

> 
> Reported-by: syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  lib/generic-radix-tree.c | 32 ++++++++++++++++++++++++++------
>  1 file changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c
> index ae25e2fa2187..f25eb111c051 100644
> --- a/lib/generic-radix-tree.c
> +++ b/lib/generic-radix-tree.c
> @@ -2,6 +2,7 @@
>  #include <linux/export.h>
>  #include <linux/generic-radix-tree.h>
>  #include <linux/gfp.h>
> +#include <linux/kmemleak.h>
>  
>  #define GENRADIX_ARY		(PAGE_SIZE / sizeof(struct genradix_node *))
>  #define GENRADIX_ARY_SHIFT	ilog2(GENRADIX_ARY)
> @@ -75,6 +76,27 @@ void *__genradix_ptr(struct __genradix *radix, size_t offset)
>  }
>  EXPORT_SYMBOL(__genradix_ptr);
>  
> +static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask)
> +{
> +	struct genradix_node *node;
> +
> +	node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO);
> +
> +	/*
> +	 * We're using pages (not slab allocations) directly for kernel data
> +	 * structures, so we need to explicitly inform kmemleak of them in order
> +	 * to avoid false positive memory leak reports.
> +	 */
> +	kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask);
> +	return node;
> +}
> +
> +static inline void genradix_free_node(struct genradix_node *node)
> +{
> +	kmemleak_free(node);
> +	free_page((unsigned long)node);
> +}
> +
>  /*
>   * Returns pointer to the specified byte @offset within @radix, allocating it if
>   * necessary - newly allocated slots are always zeroed out:
> @@ -97,8 +119,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  			break;
>  
>  		if (!new_node) {
> -			new_node = (void *)
> -				__get_free_page(gfp_mask|__GFP_ZERO);
> +			new_node = genradix_alloc_node(gfp_mask);
>  			if (!new_node)
>  				return NULL;
>  		}
> @@ -121,8 +142,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  		n = READ_ONCE(*p);
>  		if (!n) {
>  			if (!new_node) {
> -				new_node = (void *)
> -					__get_free_page(gfp_mask|__GFP_ZERO);
> +				new_node = genradix_alloc_node(gfp_mask);
>  				if (!new_node)
>  					return NULL;
>  			}
> @@ -133,7 +153,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  	}
>  
>  	if (new_node)
> -		free_page((unsigned long) new_node);
> +		genradix_free_node(new_node);
>  
>  	return &n->data[offset];
>  }
> @@ -191,7 +211,7 @@ static void genradix_free_recurse(struct genradix_node *n, unsigned level)
>  				genradix_free_recurse(n->children[i], level - 1);
>  	}
>  
> -	free_page((unsigned long) n);
> +	genradix_free_node(n);
>  }
>  
>  int __genradix_prealloc(struct __genradix *radix, size_t size,
> -- 
> 2.23.0
> 

^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] lib/generic-radix-tree.c: add kmemleak annotations
  2019-10-04  6:50     ` [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Eric Biggers
  2019-10-04 12:21       ` Marcelo Ricardo Leitner
@ 2019-10-04 12:27       ` Neil Horman
  2019-10-04 14:48       ` Catalin Marinas
  2 siblings, 0 replies; 7+ messages in thread
From: Neil Horman @ 2019-10-04 12:27 UTC (permalink / raw)
  To: Eric Biggers
  Cc: Andrew Morton, linux-mm, linux-sctp, linux-kernel,
	syzkaller-bugs, Catalin Marinas, Kent Overstreet, Vlad Yasevich,
	Xin Long, Marcelo Ricardo Leitner

On Thu, Oct 03, 2019 at 11:50:39PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Kmemleak is falsely reporting a leak of the slab allocation in
> sctp_stream_init_ext():
> 
> 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
>      [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
>      [...]
> 
> But it's freed later.  Kmemleak misses the allocation because its
> pointer is stored in the generic radix tree sctp_stream::out, and the
> generic radix tree uses raw pages which aren't tracked by kmemleak.
> 
> Fix this by adding the kmemleak hooks to the generic radix tree code.
> 
> Reported-by: syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> ---
>  lib/generic-radix-tree.c | 32 ++++++++++++++++++++++++++------
>  1 file changed, 26 insertions(+), 6 deletions(-)
> 
> diff --git a/lib/generic-radix-tree.c b/lib/generic-radix-tree.c
> index ae25e2fa2187..f25eb111c051 100644
> --- a/lib/generic-radix-tree.c
> +++ b/lib/generic-radix-tree.c
> @@ -2,6 +2,7 @@
>  #include <linux/export.h>
>  #include <linux/generic-radix-tree.h>
>  #include <linux/gfp.h>
> +#include <linux/kmemleak.h>
>  
>  #define GENRADIX_ARY		(PAGE_SIZE / sizeof(struct genradix_node *))
>  #define GENRADIX_ARY_SHIFT	ilog2(GENRADIX_ARY)
> @@ -75,6 +76,27 @@ void *__genradix_ptr(struct __genradix *radix, size_t offset)
>  }
>  EXPORT_SYMBOL(__genradix_ptr);
>  
> +static inline struct genradix_node *genradix_alloc_node(gfp_t gfp_mask)
> +{
> +	struct genradix_node *node;
> +
> +	node = (struct genradix_node *)__get_free_page(gfp_mask|__GFP_ZERO);
> +
> +	/*
> +	 * We're using pages (not slab allocations) directly for kernel data
> +	 * structures, so we need to explicitly inform kmemleak of them in order
> +	 * to avoid false positive memory leak reports.
> +	 */
> +	kmemleak_alloc(node, PAGE_SIZE, 1, gfp_mask);
> +	return node;
> +}
> +
> +static inline void genradix_free_node(struct genradix_node *node)
> +{
> +	kmemleak_free(node);
> +	free_page((unsigned long)node);
> +}
> +
>  /*
>   * Returns pointer to the specified byte @offset within @radix, allocating it if
>   * necessary - newly allocated slots are always zeroed out:
> @@ -97,8 +119,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  			break;
>  
>  		if (!new_node) {
> -			new_node = (void *)
> -				__get_free_page(gfp_mask|__GFP_ZERO);
> +			new_node = genradix_alloc_node(gfp_mask);
>  			if (!new_node)
>  				return NULL;
>  		}
> @@ -121,8 +142,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  		n = READ_ONCE(*p);
>  		if (!n) {
>  			if (!new_node) {
> -				new_node = (void *)
> -					__get_free_page(gfp_mask|__GFP_ZERO);
> +				new_node = genradix_alloc_node(gfp_mask);
>  				if (!new_node)
>  					return NULL;
>  			}
> @@ -133,7 +153,7 @@ void *__genradix_ptr_alloc(struct __genradix *radix, size_t offset,
>  	}
>  
>  	if (new_node)
> -		free_page((unsigned long) new_node);
> +		genradix_free_node(new_node);
>  
>  	return &n->data[offset];
>  }
> @@ -191,7 +211,7 @@ static void genradix_free_recurse(struct genradix_node *n, unsigned level)
>  				genradix_free_recurse(n->children[i], level - 1);
>  	}
>  
> -	free_page((unsigned long) n);
> +	genradix_free_node(n);
>  }
>  
>  int __genradix_prealloc(struct __genradix *radix, size_t size,
> -- 
> 2.23.0
> 
> 
Acked-by: Neil Horman <nhorman@tuxdriver.com>


^ permalink raw reply	[flat|nested] 7+ messages in thread

* Re: [PATCH] lib/generic-radix-tree.c: add kmemleak annotations
  2019-10-04  6:50     ` [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Eric Biggers
  2019-10-04 12:21       ` Marcelo Ricardo Leitner
  2019-10-04 12:27       ` Neil Horman
@ 2019-10-04 14:48       ` Catalin Marinas
  2 siblings, 0 replies; 7+ messages in thread
From: Catalin Marinas @ 2019-10-04 14:48 UTC (permalink / raw)
  To: Eric Biggers
  Cc: Andrew Morton, linux-mm, linux-sctp, linux-kernel,
	syzkaller-bugs, Kent Overstreet, Vlad Yasevich, Xin Long,
	Neil Horman, Marcelo Ricardo Leitner

On Thu, Oct 03, 2019 at 11:50:39PM -0700, Eric Biggers wrote:
> From: Eric Biggers <ebiggers@google.com>
> 
> Kmemleak is falsely reporting a leak of the slab allocation in
> sctp_stream_init_ext():
> 
> 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
>      [<000000004483ca2b>] sctp_sendmsg+0x2a8/0x990 net/sctp/socket.c:2102
>      [...]
> 
> But it's freed later.  Kmemleak misses the allocation because its
> pointer is stored in the generic radix tree sctp_stream::out, and the
> generic radix tree uses raw pages which aren't tracked by kmemleak.
> 
> Fix this by adding the kmemleak hooks to the generic radix tree code.
> 
> Reported-by: syzbot+7f3b6b106be8dcdcdeec@syzkaller.appspotmail.com
> Signed-off-by: Eric Biggers <ebiggers@google.com>

Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>

^ permalink raw reply	[flat|nested] 7+ messages in thread

end of thread, other threads:[~2019-10-04 14:48 UTC | newest]

Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-05-31 14:58 memory leak in sctp_stream_init_ext syzbot
2019-06-04 13:36 ` Xin Long
2019-06-04 13:38   ` Dmitry Vyukov
2019-10-04  6:50     ` [PATCH] lib/generic-radix-tree.c: add kmemleak annotations Eric Biggers
2019-10-04 12:21       ` Marcelo Ricardo Leitner
2019-10-04 12:27       ` Neil Horman
2019-10-04 14:48       ` Catalin Marinas

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