| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 001/107] SELinux: Fix memory leak upon loading policy | Date | Tue, 11 Feb 2014 11:04:27 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
commit 8ed814602876bec9bad2649ca17f34b499357a1c upstream.
Hello.
I got below leak with linux-3.10.0-54.0.1.el7.x86_64 .
[ 681.903890] kmemleak: 5538 new suspected memory leaks (see /sys/kernel/debug/kmemleak)
Below is a patch, but I don't know whether we need special handing for undoing ebitmap_set_bit() call. ---------- >>From fe97527a90fe95e2239dfbaa7558f0ed559c0992 Mon Sep 17 00:00:00 2001 From: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Date: Mon, 6 Jan 2014 16:30:21 +0900 Subject: [PATCH 3.12 001/107] SELinux: Fix memory leak upon loading policy
Commit 2463c26d "SELinux: put name based create rules in a hashtable" did not check return value from hashtab_insert() in filename_trans_read(). It leaks memory if hashtab_insert() returns error.
unreferenced object 0xffff88005c9160d0 (size 8): comm "systemd", pid 1, jiffies 4294688674 (age 235.265s) hex dump (first 8 bytes): 57 0b 00 00 6b 6b 6b a5 W...kkk. backtrace: [<ffffffff816604ae>] kmemleak_alloc+0x4e/0xb0 [<ffffffff811cba5e>] kmem_cache_alloc_trace+0x12e/0x360 [<ffffffff812aec5d>] policydb_read+0xd1d/0xf70 [<ffffffff812b345c>] security_load_policy+0x6c/0x500 [<ffffffff812a623c>] sel_write_load+0xac/0x750 [<ffffffff811eb680>] vfs_write+0xc0/0x1f0 [<ffffffff811ec08c>] SyS_write+0x4c/0xa0 [<ffffffff81690419>] system_call_fastpath+0x16/0x1b [<ffffffffffffffff>] 0xffffffffffffffff
However, we should not return EEXIST error to the caller, or the systemd will show below message and the boot sequence freezes.
systemd[1]: Failed to load SELinux policy. Freezing.
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- security/selinux/ss/policydb.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-)
--- a/security/selinux/ss/policydb.c +++ b/security/selinux/ss/policydb.c @@ -1941,7 +1941,19 @@ static int filename_trans_read(struct po if (rc) goto out; - hashtab_insert(p->filename_trans, ft, otype); + rc = hashtab_insert(p->filename_trans, ft, otype); + if (rc) { + /* + * Do not return -EEXIST to the caller, or the system + * will not boot. + */ + if (rc != -EEXIST) + goto out; + /* But free memory to avoid memory leak. */ + kfree(ft); + kfree(name); + kfree(otype); + } } hash_eval(p->filename_trans, "filenametr"); return 0;
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