Re: [PATCH] SCTP: Free the per-net sysctl table on net exit. v2
From: Martin Mokrejs <hidden>
Date: 2013-03-05 09:05:15
Also in:
linux-sctp
Hi, this is to let you know that this patch is still not in stable. I just fetched 3.7.10 and reproduced the original problem. I bet this slipped through because there was an initial patch from Vlad Yasevich on Jan 24, then a follow-up patch from Eric Biedermann which did not compile and finally a v2 patch from E. B which did compile. For me the last, v2 patch applies (with some hunk) to 3.7.10 and compiles fine. Thanks, martin Eric W. Biederman wrote:
quoted hunk ↗ jump to hunk
From: Vlad Yasevich <redacted> Date: Thu, 24 Jan 2013 11:02:47 -0500 Per-net sysctl table needs to be explicitly freed at net exit. Otherwise we see the following with kmemleak: unreferenced object 0xffff880402d08000 (size 2048): comm "chrome_sandbox", pid 18437, jiffies 4310887172 (age 9097.630s) hex dump (first 32 bytes): b2 68 89 81 ff ff ff ff 20 04 04 f8 01 88 ff ff .h...... ....... 04 00 00 00 a4 01 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff815b4aad>] kmemleak_alloc+0x21/0x3e [<ffffffff81110352>] slab_post_alloc_hook+0x28/0x2a [<ffffffff81113fad>] __kmalloc_track_caller+0xf1/0x104 [<ffffffff810f10c2>] kmemdup+0x1b/0x30 [<ffffffff81571e9f>] sctp_sysctl_net_register+0x1f/0x72 [<ffffffff8155d305>] sctp_net_init+0x100/0x39f [<ffffffff814ad53c>] ops_init+0xc6/0xf5 [<ffffffff814ad5b7>] setup_net+0x4c/0xd0 [<ffffffff814ada5e>] copy_net_ns+0x6d/0xd6 [<ffffffff810938b1>] create_new_namespaces+0xd7/0x147 [<ffffffff810939f4>] copy_namespaces+0x63/0x99 [<ffffffff81076733>] copy_process+0xa65/0x1233 [<ffffffff81077030>] do_fork+0x10b/0x271 [<ffffffff8100a0e9>] sys_clone+0x23/0x25 [<ffffffff815dda73>] stub_clone+0x13/0x20 [<ffffffffffffffff>] 0xffffffffffffffff I fixed the spelling of sysctl_header so the code actually compiles. -- EWB. Reported-by: Martin Mokrejs <redacted> Signed-off-by: Vlad Yasevich <redacted> Acked-by: Neil Horman <nhorman@tuxdriver.com> Signed-off-by: "Eric W. Biederman" <redacted> --- The typo is fixed in the patch this time in addition to my test tree. net/sctp/sysctl.c | 4 ++++ 1 files changed, 4 insertions(+), 0 deletions(-)diff --git a/net/sctp/sysctl.c b/net/sctp/sysctl.c index 043889a..bf3c6e8 100644 --- a/net/sctp/sysctl.c +++ b/net/sctp/sysctl.c@@ -366,7 +366,11 @@ int sctp_sysctl_net_register(struct net *net) void sctp_sysctl_net_unregister(struct net *net) { + struct ctl_table *table; + + table = net->sctp.sysctl_header->ctl_table_arg; unregister_net_sysctl_table(net->sctp.sysctl_header); + kfree(table); } static struct ctl_table_header * sctp_sysctl_header;