Hello,
syzbot found the following crash on:
HEAD commit: cd6c84d8 Linux 5.2-rc2
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=132bd44aa00000
kernel config: https://syzkaller.appspot.com/x/.config?x=64479170dcaf0e11
dashboard link: https://syzkaller.appspot.com/bug?extid=7e2e50c8adfccd2e5041
compiler: gcc (GCC) 9.0.0 20181231 (experimental)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=114b1354a00000
C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14b7ad26a00000
IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: [email protected]
d started: state = MASTER, mcast_ifn = syz_tun, syncid = 0, id = 0
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 20.470s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 21.530s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 22.630s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 23.720s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 25.770s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 26.850s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
BUG: memory leak
unreferenced object 0xffff8881206bf700 (size 32):
comm "syz-executor761", pid 7268, jiffies 4294943441 (age 27.940s)
hex dump (first 32 bytes):
00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<0000000057619e23>] kmemleak_alloc_recursive
include/linux/kmemleak.h:55 [inline]
[<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
[<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
[<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
[<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
[<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
net/netfilter/ipvs/ip_vs_sync.c:1862
[<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
net/netfilter/ipvs/ip_vs_ctl.c:2402
[<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
[<00000000ece457c8>] nf_setsockopt+0x4c/0x80
net/netfilter/nf_sockopt.c:115
[<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
[<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
[<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
[<00000000fa895401>] sock_common_setsockopt+0x38/0x50
net/core/sock.c:3130
[<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
[<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
[<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
[<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
[<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
arch/x86/entry/common.c:301
[<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
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 [email protected].
syzbot will keep track of this bug report. See:
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syzbot can test patches for this bug, for details see:
https://goo.gl/tpsmEJ#testing-patches
On Tue, May 28, 2019 at 11:28:05AM -0700, syzbot wrote:
> Hello,
>
> syzbot found the following crash on:
>
> HEAD commit: cd6c84d8 Linux 5.2-rc2
> git tree: upstream
> console output: https://syzkaller.appspot.com/x/log.txt?x=132bd44aa00000
> kernel config: https://syzkaller.appspot.com/x/.config?x=64479170dcaf0e11
> dashboard link: https://syzkaller.appspot.com/bug?extid=7e2e50c8adfccd2e5041
> compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> syz repro: https://syzkaller.appspot.com/x/repro.syz?x=114b1354a00000
> C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14b7ad26a00000
>
> IMPORTANT: if you fix the bug, please add the following tag to the commit:
> Reported-by: [email protected]
>
> d started: state = MASTER, mcast_ifn = syz_tun, syncid = 0, id = 0
> BUG: memory leak
> unreferenced object 0xffff8881206bf700 (size 32):
> comm "syz-executor761", pid 7268, jiffies 4294943441 (age 20.470s)
> hex dump (first 32 bytes):
> 00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
> 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> backtrace:
> [<0000000057619e23>] kmemleak_alloc_recursive
> include/linux/kmemleak.h:55 [inline]
> [<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
> [<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
> [<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
> [<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
> [<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
> net/netfilter/ipvs/ip_vs_sync.c:1862
> [<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
> net/netfilter/ipvs/ip_vs_ctl.c:2402
> [<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
> [<00000000ece457c8>] nf_setsockopt+0x4c/0x80
> net/netfilter/nf_sockopt.c:115
> [<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
> [<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
> [<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
> [<00000000fa895401>] sock_common_setsockopt+0x38/0x50
> net/core/sock.c:3130
> [<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
> [<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
> [<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
> [<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
> [<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
> arch/x86/entry/common.c:301
> [<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
>
The bug is that ownership of some memory is passed to a kthread started by
kthread_run(), but the kthread can be stopped before it actually executes the
threadfn. See the code in kernel/kthread.c:
ret = -EINTR;
if (!test_bit(KTHREAD_SHOULD_STOP, &self->flags)) {
cgroup_kthread_ready();
__kthread_parkme(self);
ret = threadfn(data);
}
So, apparently the thread parameters must always be owned by the owner of the
kthread, not by the kthread itself. It seems like this would be a common
mistake in kernel code; I'm surprised this doesn't come up more...
- Eric
Hello,
On Mon, 10 Jun 2019, Eric Biggers wrote:
> On Tue, May 28, 2019 at 11:28:05AM -0700, syzbot wrote:
> > Hello,
> >
> > syzbot found the following crash on:
> >
> > HEAD commit: cd6c84d8 Linux 5.2-rc2
> > git tree: upstream
> > console output: https://syzkaller.appspot.com/x/log.txt?x=132bd44aa00000
> > kernel config: https://syzkaller.appspot.com/x/.config?x=64479170dcaf0e11
> > dashboard link: https://syzkaller.appspot.com/bug?extid=7e2e50c8adfccd2e5041
> > compiler: gcc (GCC) 9.0.0 20181231 (experimental)
> > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=114b1354a00000
> > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=14b7ad26a00000
> >
> > IMPORTANT: if you fix the bug, please add the following tag to the commit:
> > Reported-by: [email protected]
> >
> > d started: state = MASTER, mcast_ifn = syz_tun, syncid = 0, id = 0
> > BUG: memory leak
> > unreferenced object 0xffff8881206bf700 (size 32):
> > comm "syz-executor761", pid 7268, jiffies 4294943441 (age 20.470s)
> > hex dump (first 32 bytes):
> > 00 40 7c 09 81 88 ff ff 80 45 b8 21 81 88 ff ff .@|......E.!....
> > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
> > backtrace:
> > [<0000000057619e23>] kmemleak_alloc_recursive
> > include/linux/kmemleak.h:55 [inline]
> > [<0000000057619e23>] slab_post_alloc_hook mm/slab.h:439 [inline]
> > [<0000000057619e23>] slab_alloc mm/slab.c:3326 [inline]
> > [<0000000057619e23>] kmem_cache_alloc_trace+0x13d/0x280 mm/slab.c:3553
> > [<0000000086ce5479>] kmalloc include/linux/slab.h:547 [inline]
> > [<0000000086ce5479>] start_sync_thread+0x5d2/0xe10
> > net/netfilter/ipvs/ip_vs_sync.c:1862
> > [<000000001a9229cc>] do_ip_vs_set_ctl+0x4c5/0x780
> > net/netfilter/ipvs/ip_vs_ctl.c:2402
> > [<00000000ece457c8>] nf_sockopt net/netfilter/nf_sockopt.c:106 [inline]
> > [<00000000ece457c8>] nf_setsockopt+0x4c/0x80
> > net/netfilter/nf_sockopt.c:115
> > [<00000000942f62d4>] ip_setsockopt net/ipv4/ip_sockglue.c:1258 [inline]
> > [<00000000942f62d4>] ip_setsockopt+0x9b/0xb0 net/ipv4/ip_sockglue.c:1238
> > [<00000000a56a8ffd>] udp_setsockopt+0x4e/0x90 net/ipv4/udp.c:2616
> > [<00000000fa895401>] sock_common_setsockopt+0x38/0x50
> > net/core/sock.c:3130
> > [<0000000095eef4cf>] __sys_setsockopt+0x98/0x120 net/socket.c:2078
> > [<000000009747cf88>] __do_sys_setsockopt net/socket.c:2089 [inline]
> > [<000000009747cf88>] __se_sys_setsockopt net/socket.c:2086 [inline]
> > [<000000009747cf88>] __x64_sys_setsockopt+0x26/0x30 net/socket.c:2086
> > [<00000000ded8ba80>] do_syscall_64+0x76/0x1a0
> > arch/x86/entry/common.c:301
> > [<00000000893b4ac8>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
> >
>
> The bug is that ownership of some memory is passed to a kthread started by
> kthread_run(), but the kthread can be stopped before it actually executes the
> threadfn. See the code in kernel/kthread.c:
>
> ret = -EINTR;
> if (!test_bit(KTHREAD_SHOULD_STOP, &self->flags)) {
> cgroup_kthread_ready();
> __kthread_parkme(self);
> ret = threadfn(data);
> }
>
> So, apparently the thread parameters must always be owned by the owner of the
> kthread, not by the kthread itself. It seems like this would be a common
> mistake in kernel code; I'm surprised this doesn't come up more...
Thanks! It explains the problem. It was not obvious from the
fact that only tinfo was reported as a leak, nothing for tinfo->sock.
Moving sock_release to owner complicates the locking but
I'll try to fix it in the following days...
Regards
--
Julian Anastasov <[email protected]>