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author | Felix Fietkau <nbd@openwrt.org> | 2016-01-19 21:09:17 +0000 |
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committer | Felix Fietkau <nbd@openwrt.org> | 2016-01-19 21:09:17 +0000 |
commit | e62802752ed1ff48f9b1007d927f61be51a85cbc (patch) | |
tree | 1d1fddc89ab12115b429d9c6bbe627099fe225c2 /target/linux/generic/patches-4.3 | |
parent | 20ba5a01cfa46a3c56dc26b57f2f922afba61a4b (diff) | |
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kernel: fix keyring reference leak (CVE-2016-0728)
Signed-off-by: Felix Fietkau <nbd@openwrt.org>
SVN-Revision: 48372
Diffstat (limited to 'target/linux/generic/patches-4.3')
-rw-r--r-- | target/linux/generic/patches-4.3/010-KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch | 75 |
1 files changed, 75 insertions, 0 deletions
diff --git a/target/linux/generic/patches-4.3/010-KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch b/target/linux/generic/patches-4.3/010-KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch new file mode 100644 index 0000000..9c6a969 --- /dev/null +++ b/target/linux/generic/patches-4.3/010-KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch @@ -0,0 +1,75 @@ +From 7ca88764d45c209791e8813131c1457c2e9e51e7 Mon Sep 17 00:00:00 2001 +From: Yevgeny Pats <yevgeny@perception-point.io> +Date: Mon, 11 Jan 2016 12:05:28 +0000 +Subject: KEYS: Fix keyring ref leak in join_session_keyring() + +If a thread is asked to join as a session keyring the keyring that's already +set as its session, we leak a keyring reference. + +This can be tested with the following program: + + #include <stddef.h> + #include <stdio.h> + #include <sys/types.h> + #include <keyutils.h> + + int main(int argc, const char *argv[]) + { + int i = 0; + key_serial_t serial; + + serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING, + "leaked-keyring"); + if (serial < 0) { + perror("keyctl"); + return -1; + } + + if (keyctl(KEYCTL_SETPERM, serial, + KEY_POS_ALL | KEY_USR_ALL) < 0) { + perror("keyctl"); + return -1; + } + + for (i = 0; i < 100; i++) { + serial = keyctl(KEYCTL_JOIN_SESSION_KEYRING, + "leaked-keyring"); + if (serial < 0) { + perror("keyctl"); + return -1; + } + } + + return 0; + } + +If, after the program has run, there something like the following line in +/proc/keys: + +3f3d898f I--Q--- 100 perm 3f3f0000 0 0 keyring leaked-keyring: empty + +with a usage count of 100 * the number of times the program has been run, +then the kernel is malfunctioning. If leaked-keyring has zero usages or +has been garbage collected, then the problem is fixed. + +Reported-by: Yevgeny Pats <yevgeny@perception-point.io> +Signed-off-by: David Howells <dhowells@redhat.com> +--- + security/keys/process_keys.c | 1 + + 1 file changed, 1 insertion(+) + +diff --git a/security/keys/process_keys.c b/security/keys/process_keys.c +index a3f85d2..e6d50172 100644 +--- a/security/keys/process_keys.c ++++ b/security/keys/process_keys.c +@@ -794,6 +794,7 @@ long join_session_keyring(const char *name) + ret = PTR_ERR(keyring); + goto error2; + } else if (keyring == new->session_keyring) { ++ key_put(keyring); + ret = 0; + goto error2; + } +-- +2.7.0.rc3 + |