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| author | Tyler Hicks <tyhicks@linux.microsoft.com> | 2020-07-09 01:19:02 -0500 |
|---|---|---|
| committer | Mimi Zohar <zohar@linux.ibm.com> | 2020-07-16 21:53:55 -0400 |
| commit | 2bdd737c5687d6dec30e205953146ede8a87dbdd (patch) | |
| tree | a47455cea960141922e1b797f4bb5eea59a26743 /security | |
| parent | 465aee77aae857b5fcde56ee192b33dc369fba04 (diff) | |
| download | linux-2bdd737c5687d6dec30e205953146ede8a87dbdd.tar.gz linux-2bdd737c5687d6dec30e205953146ede8a87dbdd.tar.bz2 linux-2bdd737c5687d6dec30e205953146ede8a87dbdd.zip | |
ima: Free the entire rule if it fails to parse
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>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/ima/ima_policy.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/security/integrity/ima/ima_policy.c b/security/integrity/ima/ima_policy.c index bf00b966e87f..e458cd47c099 100644 --- a/security/integrity/ima/ima_policy.c +++ b/security/integrity/ima/ima_policy.c @@ -913,6 +913,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry, if (ima_rules == &ima_default_rules) { kfree(entry->lsm[lsm_rule].args_p); + entry->lsm[lsm_rule].args_p = NULL; result = -EINVAL; } else result = 0; @@ -1404,7 +1405,7 @@ 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); |