From: Christian Göttsche cgzones@googlemail.com
commit cad140d00899e7a9cb6fe93b282051df589e671c upstream.
`selinux_add_opt()` stopped taking ownership of the passed context since commit 70f4169ab421 ("selinux: parse contexts for mount options early").
unreferenced object 0xffff888114dfd140 (size 64): comm "mount", pid 15182, jiffies 4295687028 (age 796.340s) hex dump (first 32 bytes): 73 79 73 74 65 6d 5f 75 3a 6f 62 6a 65 63 74 5f system_u:object_ 72 3a 74 65 73 74 5f 66 69 6c 65 73 79 73 74 65 r:test_filesyste backtrace: [<ffffffffa07dbef4>] kmemdup_nul+0x24/0x80 [<ffffffffa0d34253>] selinux_sb_eat_lsm_opts+0x293/0x560 [<ffffffffa0d13f08>] security_sb_eat_lsm_opts+0x58/0x80 [<ffffffffa0af1eb2>] generic_parse_monolithic+0x82/0x180 [<ffffffffa0a9c1a5>] do_new_mount+0x1f5/0x550 [<ffffffffa0a9eccb>] path_mount+0x2ab/0x1570 [<ffffffffa0aa019e>] __x64_sys_mount+0x20e/0x280 [<ffffffffa1f47124>] do_syscall_64+0x34/0x80 [<ffffffffa200007e>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
unreferenced object 0xffff888108e71640 (size 64): comm "fsmount", pid 7607, jiffies 4295044974 (age 1601.016s) hex dump (first 32 bytes): 73 79 73 74 65 6d 5f 75 3a 6f 62 6a 65 63 74 5f system_u:object_ 72 3a 74 65 73 74 5f 66 69 6c 65 73 79 73 74 65 r:test_filesyste backtrace: [<ffffffff861dc2b1>] memdup_user+0x21/0x90 [<ffffffff861dc367>] strndup_user+0x47/0xa0 [<ffffffff864f6965>] __do_sys_fsconfig+0x485/0x9f0 [<ffffffff87940124>] do_syscall_64+0x34/0x80 [<ffffffff87a0007e>] entry_SYSCALL_64_after_hwframe+0x46/0xb0
Cc: stable@vger.kernel.org Fixes: 70f4169ab421 ("selinux: parse contexts for mount options early") Signed-off-by: Christian Göttsche cgzones@googlemail.com Signed-off-by: Paul Moore paul@paul-moore.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- security/selinux/hooks.c | 11 ++++------- 1 file changed, 4 insertions(+), 7 deletions(-)
--- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2600,8 +2600,9 @@ static int selinux_sb_eat_lsm_opts(char } } rc = selinux_add_opt(token, arg, mnt_opts); + kfree(arg); + arg = NULL; if (unlikely(rc)) { - kfree(arg); goto free_opt; } } else { @@ -2792,17 +2793,13 @@ static int selinux_fs_context_parse_para struct fs_parameter *param) { struct fs_parse_result result; - int opt, rc; + int opt;
opt = fs_parse(fc, selinux_fs_parameters, param, &result); if (opt < 0) return opt;
- rc = selinux_add_opt(opt, param->string, &fc->security); - if (!rc) - param->string = NULL; - - return rc; + return selinux_add_opt(opt, param->string, &fc->security); }
/* inode security operations */