From: Xiyu Yang Date: Sun, 5 Apr 2020 05:11:55 +0000 (+0800) Subject: apparmor: fix potential label refcnt leak in aa_change_profile X-Git-Tag: v4.19.125~37 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=dd73adb161fec02d9303ce98e0e5bf844c5d791e;p=thirdparty%2Fkernel%2Fstable.git apparmor: fix potential label refcnt leak in aa_change_profile commit a0b845ffa0d91855532b50fc040aeb2d8338dca4 upstream. aa_change_profile() invokes aa_get_current_label(), which returns a reference of the current task's label. According to the comment of aa_get_current_label(), the returned reference must be put with aa_put_label(). However, when the original object pointed by "label" becomes unreachable because aa_change_profile() returns or a new object is assigned to "label", reference count increased by aa_get_current_label() is not decreased, causing a refcnt leak. Fix this by calling aa_put_label() before aa_change_profile() return and dropping unnecessary aa_get_current_label(). Fixes: 9fcf78cca198 ("apparmor: update domain transitions that are subsets of confinement at nnp") Signed-off-by: Xiyu Yang Signed-off-by: Xin Tan Signed-off-by: John Johansen Signed-off-by: Greg Kroah-Hartman --- diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index bdf9e4cefe259..b9d5b3459705b 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -1338,6 +1338,7 @@ int aa_change_profile(const char *fqname, int flags) ctx->nnp = aa_get_label(label); if (!fqname || !*fqname) { + aa_put_label(label); AA_DEBUG("no profile name"); return -EINVAL; } @@ -1356,8 +1357,6 @@ int aa_change_profile(const char *fqname, int flags) op = OP_CHANGE_PROFILE; } - label = aa_get_current_label(); - if (*fqname == '&') { stack = true; /* don't have label_parse() do stacking */