ima: Free the entire rule if it fails to parse
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: f1b08bbcbd
("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>
This commit is contained in:
parent
3d55a948aa
commit
f039564c36
@ -662,6 +662,7 @@ static int ima_lsm_rule_init(struct ima_rule_entry *entry,
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&entry->lsm[lsm_rule].rule);
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if (!entry->lsm[lsm_rule].rule) {
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kfree(entry->lsm[lsm_rule].args_p);
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entry->lsm[lsm_rule].args_p = NULL;
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return -EINVAL;
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}
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@ -1034,7 +1035,7 @@ ssize_t ima_parse_add_rule(char *rule)
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result = ima_parse_rule(p, entry);
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if (result) {
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kfree(entry);
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ima_free_rule(entry);
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integrity_audit_msg(AUDIT_INTEGRITY_STATUS, NULL,
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NULL, op, "invalid-policy", result,
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audit_info);
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