Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge branch 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull key handling bugfix from James Morris:
"Fix a race between keyctl_read() and keyctl_revoke()"
* 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
KEYS: Fix race between read and revoke
+9
-9
+9
-9
security/keys/keyctl.c
+9
-9
security/keys/keyctl.c
···
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/* the key is probably readable - now try to read it */
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can_read_key:
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-
ret = key_validate(key);
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-
if (ret == 0) {
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-
ret = -EOPNOTSUPP;
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-
if (key->type->read) {
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/* read the data with the semaphore held (since we
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-
* might sleep) */
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-
down_read(&key->sem);
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+
ret = -EOPNOTSUPP;
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+
if (key->type->read) {
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+
/* Read the data with the semaphore held (since we might sleep)
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+
* to protect against the key being updated or revoked.
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+
*/
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down_read(&key->sem);
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ret = key_validate(key);
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+
if (ret == 0)
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ret = key->type->read(key, buffer, buflen);
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-
up_read(&key->sem);
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-
}
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+
up_read(&key->sem);
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}
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error2: