From: Tyler Hicks tyhicks@linux.microsoft.com
commit 2bdd737c5687d6dec30e205953146ede8a87dbdd upstream.
Use ima_free_rule() to fix memory leaks of allocated ima_rule_entry members, such as .fsname and .keyrings, when an error is encountered during rule parsing.
Set the args_p pointer to NULL after freeing it in the error path of ima_lsm_rule_init() so that it isn't freed twice.
This fixes a memory leak seen when loading an rule that contains an additional piece of allocated memory, such as an fsname, followed by an invalid conditional:
# echo "measure fsname=tmpfs bad=cond" > /sys/kernel/security/ima/policy -bash: echo: write error: Invalid argument # echo scan > /sys/kernel/debug/kmemleak # cat /sys/kernel/debug/kmemleak unreferenced object 0xffff98e7e4ece6c0 (size 8): comm "bash", pid 672, jiffies 4294791843 (age 21.855s) hex dump (first 8 bytes): 74 6d 70 66 73 00 6b a5 tmpfs.k. backtrace: [<00000000abab7413>] kstrdup+0x2e/0x60 [<00000000f11ede32>] ima_parse_add_rule+0x7d4/0x1020 [<00000000f883dd7a>] ima_write_policy+0xab/0x1d0 [<00000000b17cf753>] vfs_write+0xde/0x1d0 [<00000000b8ddfdea>] ksys_write+0x68/0xe0 [<00000000b8e21e87>] do_syscall_64+0x56/0xa0 [<0000000089ea7b98>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
Fixes: f1b08bbcbdaf ("ima: define a new policy condition based on the filesystem name") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks tyhicks@linux.microsoft.com Signed-off-by: Mimi Zohar zohar@linux.ibm.com Cc: stable@vger.kernel.org # 4.19+ Signed-off-by: Gou Hao gouhao@uniontech.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- security/integrity/ima/ima_policy.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
--- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -662,6 +662,7 @@ static int ima_lsm_rule_init(struct ima_ &entry->lsm[lsm_rule].rule); if (!entry->lsm[lsm_rule].rule) { kfree(entry->lsm[lsm_rule].args_p); + entry->lsm[lsm_rule].args_p = NULL; return -EINVAL; }
@@ -1034,7 +1035,7 @@ ssize_t ima_parse_add_rule(char *rule)
result = ima_parse_rule(p, entry); if (result) { - kfree(entry); + ima_free_rule(entry); integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL, NULL, op, "invalid-policy", result, audit_info);