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authorKonstantin Khlebnikov <k.khlebnikov@samsung.com>2014-08-07 20:52:43 +0400
committerCasey Schaufler <casey@schaufler-ca.com>2014-08-08 14:51:07 -0700
commitb862e561bad6372872f5bf98d95f4131d265b110 (patch)
tree86df1aa1baae0401ede16a22748bef65ca345ea3 /security/smack/smackfs.c
parentfd5c9d230d2ac8a2594dfd15f0cca678fd7a64c7 (diff)
downloadlinux-b862e561bad6372872f5bf98d95f4131d265b110.tar.gz
Smack: handle zero-length security labels without panic
Zero-length security labels are invalid but kernel should handle them. This patch fixes kernel panic after setting zero-length security labels: # attr -S -s "SMACK64" -V "" file And after writing zero-length string into smackfs files syslog and onlycp: # python -c 'import os; os.write(1, "")' > /smack/syslog The problem is caused by brain-damaged logic in function smk_parse_smack() which takes pointer to buffer and its length but if length below or equal zero it thinks that the buffer is zero-terminated. Unfortunately callers of this function are widely used and proper fix requires serious refactoring. Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Diffstat (limited to 'security/smack/smackfs.c')
-rw-r--r--security/smack/smackfs.c4
1 files changed, 2 insertions, 2 deletions
diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c
index 3c720ff10591..56a1439786a9 100644
--- a/security/smack/smackfs.c
+++ b/security/smack/smackfs.c
@@ -1677,7 +1677,7 @@ static ssize_t smk_write_onlycap(struct file *file, const char __user *buf,
if (smack_onlycap != NULL && smack_onlycap != skp)
return -EPERM;
- data = kzalloc(count, GFP_KERNEL);
+ data = kzalloc(count + 1, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;
@@ -2228,7 +2228,7 @@ static ssize_t smk_write_syslog(struct file *file, const char __user *buf,
if (!smack_privileged(CAP_MAC_ADMIN))
return -EPERM;
- data = kzalloc(count, GFP_KERNEL);
+ data = kzalloc(count + 1, GFP_KERNEL);
if (data == NULL)
return -ENOMEM;