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| author | Konstantin Khlebnikov <k.khlebnikov@samsung.com> | 2014-08-07 20:52:43 +0400 |
|---|---|---|
| committer | Stephane Desneux <stephane.desneux@open.eurogiciel.org> | 2015-02-04 11:23:24 +0100 |
| commit | 0b30ecad09f1d9da7a1223232216377814a1529d (patch) | |
| tree | 1f8188d9b765efebec2bb34e5f71ba813ee7a0f8 | |
| parent | ab16bd33974246516dee2b97c020bd62310ddd65 (diff) | |
| download | linux-stable-0b30ecad09f1d9da7a1223232216377814a1529d.tar.gz linux-stable-0b30ecad09f1d9da7a1223232216377814a1529d.tar.bz2 linux-stable-0b30ecad09f1d9da7a1223232216377814a1529d.zip | |
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:
And after writing zero-length string into smackfs files syslog and onlycp:
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.
Change-Id: I931735ccfaea4d8d2f0a98eacf8467f0a8359bc6
Signed-off-by: Konstantin Khlebnikov <k.khlebnikov@samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
| -rw-r--r-- | security/smack/smack_lsm.c | 2 | ||||
| -rw-r--r-- | security/smack/smackfs.c | 4 |
2 files changed, 3 insertions, 3 deletions
diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c index 84735763731b..7bd0363316c0 100644 --- a/security/smack/smack_lsm.c +++ b/security/smack/smack_lsm.c @@ -923,7 +923,7 @@ static int smack_inode_setxattr(struct dentry *dentry, const char *name, rc = -EPERM; if (rc == 0 && check_import) { - skp = smk_import_entry(value, size); + skp = size ? smk_import_entry(value, size) : NULL; if (skp == NULL || (check_star && (skp == &smack_known_star || skp == &smack_known_web))) rc = -EINVAL; diff --git a/security/smack/smackfs.c b/security/smack/smackfs.c index 32b248820840..585bea05275b 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; |