* memory leak in sctp_stream_init
@ 2019-12-15 20:35 syzbot
2019-12-16 11:48 ` Neil Horman
0 siblings, 1 reply; 5+ messages in thread
From: syzbot @ 2019-12-15 20:35 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: e31736d9 Merge tag 'nios2-v5.5-rc2' of git://git.kernel.or..
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=126a177ee00000
kernel config: https://syzkaller.appspot.com/x/.config?x=bbf3a35184a3ed64
dashboard link: https://syzkaller.appspot.com/bug?extid=772d9e36c490b18d51d1
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15602ddee00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12798251e00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+772d9e36c490b18d51d1@syzkaller.appspotmail.com
BUG: memory leak
unreferenced object 0xffff8881080a3000 (size 4096):
comm "syz-executor474", pid 7155, jiffies 4294942658 (age 15.870s)
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:
[<00000000df094087>] genradix_alloc_node lib/generic-radix-tree.c:90
[inline]
[<00000000df094087>] __genradix_ptr_alloc+0xf5/0x250
lib/generic-radix-tree.c:122
[<0000000057cfa7bb>] __genradix_prealloc+0x46/0x70
lib/generic-radix-tree.c:223
[<0000000029d02dac>] sctp_stream_alloc_out.part.0+0x57/0x80
net/sctp/stream.c:86
[<00000000bb930a04>] sctp_stream_alloc_out net/sctp/stream.c:151
[inline]
[<00000000bb930a04>] sctp_stream_init+0x129/0x180 net/sctp/stream.c:129
[<00000000ba13c246>] sctp_association_init net/sctp/associola.c:229
[inline]
[<00000000ba13c246>] sctp_association_new+0x46e/0x700
net/sctp/associola.c:295
[<000000008eb57b4d>] sctp_connect_new_asoc+0x90/0x220
net/sctp/socket.c:1070
[<00000000ea24e048>] __sctp_connect+0x182/0x3b0 net/sctp/socket.c:1176
[<00000000aa2c530a>] __sctp_setsockopt_connectx+0xa9/0xf0
net/sctp/socket.c:1322
[<0000000018934bfd>] sctp_getsockopt_connectx3 net/sctp/socket.c:1407
[inline]
[<0000000018934bfd>] sctp_getsockopt net/sctp/socket.c:8079 [inline]
[<0000000018934bfd>] sctp_getsockopt+0x1394/0x32f6
net/sctp/socket.c:8010
[<000000005fd7e3c8>] sock_common_getsockopt+0x38/0x50
net/core/sock.c:3108
[<00000000333baf72>] __sys_getsockopt+0xa8/0x180 net/socket.c:2162
[<00000000de0f98e4>] __do_sys_getsockopt net/socket.c:2177 [inline]
[<00000000de0f98e4>] __se_sys_getsockopt net/socket.c:2174 [inline]
[<00000000de0f98e4>] __x64_sys_getsockopt+0x26/0x30 net/socket.c:2174
[<00000000cf1dfee9>] do_syscall_64+0x73/0x220
arch/x86/entry/common.c:294
[<000000000f416860>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
---
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] 5+ messages in thread* Re: memory leak in sctp_stream_init 2019-12-15 20:35 memory leak in sctp_stream_init syzbot @ 2019-12-16 11:48 ` Neil Horman 2019-12-16 14:56 ` Marcelo Ricardo Leitner 0 siblings, 1 reply; 5+ messages in thread From: Neil Horman @ 2019-12-16 11:48 UTC (permalink / raw) To: syzbot Cc: davem, linux-kernel, linux-sctp, marcelo.leitner, netdev, syzkaller-bugs, vyasevich On Sun, Dec 15, 2019 at 12:35:09PM -0800, syzbot wrote: > Hello, > > syzbot found the following crash on: > > HEAD commit: e31736d9 Merge tag 'nios2-v5.5-rc2' of git://git.kernel.or.. > git tree: upstream > console output: https://syzkaller.appspot.com/x/log.txt?x=126a177ee00000 > kernel config: https://syzkaller.appspot.com/x/.config?x=bbf3a35184a3ed64 > dashboard link: https://syzkaller.appspot.com/bug?extid=772d9e36c490b18d51d1 > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15602ddee00000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12798251e00000 > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > Reported-by: syzbot+772d9e36c490b18d51d1@syzkaller.appspotmail.com > > BUG: memory leak > unreferenced object 0xffff8881080a3000 (size 4096): > comm "syz-executor474", pid 7155, jiffies 4294942658 (age 15.870s) > 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: > [<00000000df094087>] genradix_alloc_node lib/generic-radix-tree.c:90 > [inline] > [<00000000df094087>] __genradix_ptr_alloc+0xf5/0x250 > lib/generic-radix-tree.c:122 > [<0000000057cfa7bb>] __genradix_prealloc+0x46/0x70 > lib/generic-radix-tree.c:223 > [<0000000029d02dac>] sctp_stream_alloc_out.part.0+0x57/0x80 > net/sctp/stream.c:86 > [<00000000bb930a04>] sctp_stream_alloc_out net/sctp/stream.c:151 > [inline] > [<00000000bb930a04>] sctp_stream_init+0x129/0x180 net/sctp/stream.c:129 > [<00000000ba13c246>] sctp_association_init net/sctp/associola.c:229 > [inline] > [<00000000ba13c246>] sctp_association_new+0x46e/0x700 > net/sctp/associola.c:295 > [<000000008eb57b4d>] sctp_connect_new_asoc+0x90/0x220 > net/sctp/socket.c:1070 > [<00000000ea24e048>] __sctp_connect+0x182/0x3b0 net/sctp/socket.c:1176 > [<00000000aa2c530a>] __sctp_setsockopt_connectx+0xa9/0xf0 > net/sctp/socket.c:1322 > [<0000000018934bfd>] sctp_getsockopt_connectx3 net/sctp/socket.c:1407 > [inline] > [<0000000018934bfd>] sctp_getsockopt net/sctp/socket.c:8079 [inline] > [<0000000018934bfd>] sctp_getsockopt+0x1394/0x32f6 > net/sctp/socket.c:8010 > [<000000005fd7e3c8>] sock_common_getsockopt+0x38/0x50 > net/core/sock.c:3108 > [<00000000333baf72>] __sys_getsockopt+0xa8/0x180 net/socket.c:2162 > [<00000000de0f98e4>] __do_sys_getsockopt net/socket.c:2177 [inline] > [<00000000de0f98e4>] __se_sys_getsockopt net/socket.c:2174 [inline] > [<00000000de0f98e4>] __x64_sys_getsockopt+0x26/0x30 net/socket.c:2174 > [<00000000cf1dfee9>] do_syscall_64+0x73/0x220 > arch/x86/entry/common.c:294 > [<000000000f416860>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > Almost looks like we're processing a connectx socket option while the handling of a cookie echo chunk is in flight through the state machine (i.e. sctp_stream_update is getting called on the association while we're setting it up in parallel), though I'm not sure how that can happen Neil > > > --- > 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] 5+ messages in thread
* Re: memory leak in sctp_stream_init 2019-12-16 11:48 ` Neil Horman @ 2019-12-16 14:56 ` Marcelo Ricardo Leitner 2019-12-17 0:37 ` Marcelo Ricardo Leitner 0 siblings, 1 reply; 5+ messages in thread From: Marcelo Ricardo Leitner @ 2019-12-16 14:56 UTC (permalink / raw) To: Neil Horman Cc: syzbot, davem, linux-kernel, linux-sctp, netdev, syzkaller-bugs, vyasevich On Mon, Dec 16, 2019 at 06:48:28AM -0500, Neil Horman wrote: > On Sun, Dec 15, 2019 at 12:35:09PM -0800, syzbot wrote: > > Hello, > > > > syzbot found the following crash on: > > > > HEAD commit: e31736d9 Merge tag 'nios2-v5.5-rc2' of git://git.kernel.or.. > > git tree: upstream > > console output: https://syzkaller.appspot.com/x/log.txt?x=126a177ee00000 > > kernel config: https://syzkaller.appspot.com/x/.config?x=bbf3a35184a3ed64 > > dashboard link: https://syzkaller.appspot.com/bug?extid=772d9e36c490b18d51d1 > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=15602ddee00000 > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=12798251e00000 > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > Reported-by: syzbot+772d9e36c490b18d51d1@syzkaller.appspotmail.com > > > > BUG: memory leak > > unreferenced object 0xffff8881080a3000 (size 4096): > > comm "syz-executor474", pid 7155, jiffies 4294942658 (age 15.870s) > > 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: > > [<00000000df094087>] genradix_alloc_node lib/generic-radix-tree.c:90 > > [inline] > > [<00000000df094087>] __genradix_ptr_alloc+0xf5/0x250 > > lib/generic-radix-tree.c:122 > > [<0000000057cfa7bb>] __genradix_prealloc+0x46/0x70 > > lib/generic-radix-tree.c:223 > > [<0000000029d02dac>] sctp_stream_alloc_out.part.0+0x57/0x80 > > net/sctp/stream.c:86 > > [<00000000bb930a04>] sctp_stream_alloc_out net/sctp/stream.c:151 > > [inline] > > [<00000000bb930a04>] sctp_stream_init+0x129/0x180 net/sctp/stream.c:129 > > [<00000000ba13c246>] sctp_association_init net/sctp/associola.c:229 > > [inline] > > [<00000000ba13c246>] sctp_association_new+0x46e/0x700 > > net/sctp/associola.c:295 > > [<000000008eb57b4d>] sctp_connect_new_asoc+0x90/0x220 > > net/sctp/socket.c:1070 > > [<00000000ea24e048>] __sctp_connect+0x182/0x3b0 net/sctp/socket.c:1176 > > [<00000000aa2c530a>] __sctp_setsockopt_connectx+0xa9/0xf0 > > net/sctp/socket.c:1322 > > [<0000000018934bfd>] sctp_getsockopt_connectx3 net/sctp/socket.c:1407 > > [inline] > > [<0000000018934bfd>] sctp_getsockopt net/sctp/socket.c:8079 [inline] > > [<0000000018934bfd>] sctp_getsockopt+0x1394/0x32f6 > > net/sctp/socket.c:8010 > > [<000000005fd7e3c8>] sock_common_getsockopt+0x38/0x50 > > net/core/sock.c:3108 > > [<00000000333baf72>] __sys_getsockopt+0xa8/0x180 net/socket.c:2162 > > [<00000000de0f98e4>] __do_sys_getsockopt net/socket.c:2177 [inline] > > [<00000000de0f98e4>] __se_sys_getsockopt net/socket.c:2174 [inline] > > [<00000000de0f98e4>] __x64_sys_getsockopt+0x26/0x30 net/socket.c:2174 > > [<00000000cf1dfee9>] do_syscall_64+0x73/0x220 > > arch/x86/entry/common.c:294 > > [<000000000f416860>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 > > > > Almost looks like we're processing a connectx socket option while the handling > of a cookie echo chunk is in flight through the state machine (i.e. > sctp_stream_update is getting called on the association while we're setting it > up in parallel), though I'm not sure how that can happen I'm seeing something different. In the console output there were 2 fault injections and they hit the genradix preallocation. And our handling of that error within genradix is the responsible for it: sctp_stream_alloc_out() { ... ret = genradix_prealloc(&stream->out, outcnt, gfp); if (ret) return ret; stream->outcnt = outcnt; } int __genradix_prealloc(struct __genradix *radix, size_t size, gfp_t gfp_mask) { size_t offset; for (offset = 0; offset < size; offset += PAGE_SIZE) if (!__genradix_ptr_alloc(radix, offset, gfp_mask)) return -ENOMEM; return 0; } Note how it (and also __genradix_ptr_alloc()) doesn't clean up the already, newly initialized, indexes. Then it doesn't clean up the partially pre-allocated items on error handling: sctp_stream_init() { ... ret = sctp_stream_alloc_out(stream, outcnt, gfp); if (ret) goto out; ... ret = sctp_stream_alloc_in(stream, incnt, gfp); if (ret) { sched->free(stream); genradix_free(&stream->out); <-- stream->outcnt = 0; goto out; } out: return ret; } Considering that genradix_prealloc() failure is not fatal, seems the fix here is to just ignore the failure in sctp_stream_alloc_out() and let genradix try again later on. Marcelo ^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: memory leak in sctp_stream_init 2019-12-16 14:56 ` Marcelo Ricardo Leitner @ 2019-12-17 0:37 ` Marcelo Ricardo Leitner 2019-12-17 11:53 ` Neil Horman 0 siblings, 1 reply; 5+ messages in thread From: Marcelo Ricardo Leitner @ 2019-12-17 0:37 UTC (permalink / raw) To: Neil Horman Cc: syzbot, davem, linux-kernel, linux-sctp, netdev, syzkaller-bugs, vyasevich On Mon, Dec 16, 2019 at 11:56:38AM -0300, Marcelo Ricardo Leitner wrote: ... > Considering that genradix_prealloc() failure is not fatal, seems the > fix here is to just ignore the failure in sctp_stream_alloc_out() and > let genradix try again later on. Better yet, this fixes it here: ---8<--- diff --git a/net/sctp/stream.c b/net/sctp/stream.c index df60b5ef24cb..e0b01bf912b3 100644 --- a/net/sctp/stream.c +++ b/net/sctp/stream.c @@ -84,8 +84,10 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt, return 0; ret = genradix_prealloc(&stream->out, outcnt, gfp); - if (ret) + if (ret) { + genradix_free(&stream->out); return ret; + } stream->outcnt = outcnt; return 0; @@ -100,8 +102,10 @@ static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt, return 0; ret = genradix_prealloc(&stream->in, incnt, gfp); - if (ret) + if (ret) { + genradix_free(&stream->in); return ret; + } stream->incnt = incnt; return 0; ^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: memory leak in sctp_stream_init 2019-12-17 0:37 ` Marcelo Ricardo Leitner @ 2019-12-17 11:53 ` Neil Horman 0 siblings, 0 replies; 5+ messages in thread From: Neil Horman @ 2019-12-17 11:53 UTC (permalink / raw) To: Marcelo Ricardo Leitner Cc: syzbot, davem, linux-kernel, linux-sctp, netdev, syzkaller-bugs, vyasevich On Mon, Dec 16, 2019 at 09:37:16PM -0300, Marcelo Ricardo Leitner wrote: > On Mon, Dec 16, 2019 at 11:56:38AM -0300, Marcelo Ricardo Leitner wrote: > ... > > Considering that genradix_prealloc() failure is not fatal, seems the > > fix here is to just ignore the failure in sctp_stream_alloc_out() and > > let genradix try again later on. > > Better yet, this fixes it here: > > ---8<--- > > diff --git a/net/sctp/stream.c b/net/sctp/stream.c > index df60b5ef24cb..e0b01bf912b3 100644 > --- a/net/sctp/stream.c > +++ b/net/sctp/stream.c > @@ -84,8 +84,10 @@ static int sctp_stream_alloc_out(struct sctp_stream *stream, __u16 outcnt, > return 0; > > ret = genradix_prealloc(&stream->out, outcnt, gfp); > - if (ret) > + if (ret) { > + genradix_free(&stream->out); > return ret; > + } > > stream->outcnt = outcnt; > return 0; > @@ -100,8 +102,10 @@ static int sctp_stream_alloc_in(struct sctp_stream *stream, __u16 incnt, > return 0; > > ret = genradix_prealloc(&stream->in, incnt, gfp); > - if (ret) > + if (ret) { > + genradix_free(&stream->in); > return ret; > + } > > stream->incnt = incnt; > return 0; > I get how that fixes this, but that doesn't really seem like the right fix in my mind. Shouldn't genradix_prealloc internally free any memory its allocated if it fails part way through its operation? Neil ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2019-12-17 11:54 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2019-12-15 20:35 memory leak in sctp_stream_init syzbot 2019-12-16 11:48 ` Neil Horman 2019-12-16 14:56 ` Marcelo Ricardo Leitner 2019-12-17 0:37 ` Marcelo Ricardo Leitner 2019-12-17 11:53 ` Neil Horman
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