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author | Ben Hutchings <ben@decadent.org.uk> | 2016-01-19 00:40:41 +0000 |
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committer | Ben Hutchings <ben@decadent.org.uk> | 2016-01-19 00:41:25 +0000 |
commit | e9490659aaedd81d48f783c9df4852e2d16ee8e4 (patch) | |
tree | 9b14a47518c130e1f782954b4c21a2f2be15be0b | |
parent | e90dec2a0e7ec5abd38a474075ab0e1333c45ac1 (diff) | |
download | kernel_replicant_linux-e9490659aaedd81d48f783c9df4852e2d16ee8e4.tar.gz kernel_replicant_linux-e9490659aaedd81d48f783c9df4852e2d16ee8e4.tar.bz2 kernel_replicant_linux-e9490659aaedd81d48f783c9df4852e2d16ee8e4.zip |
KEYS: Fix keyring ref leak in join_session_keyring() (CVE-2016-0728)
-rw-r--r-- | debian/changelog | 1 | ||||
-rw-r--r-- | debian/patches/bugfix/all/KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch | 75 | ||||
-rw-r--r-- | debian/patches/series | 1 |
3 files changed, 77 insertions, 0 deletions
diff --git a/debian/changelog b/debian/changelog index c0be2e4c4aea..0c420af61530 100644 --- a/debian/changelog +++ b/debian/changelog @@ -26,6 +26,7 @@ linux (4.3.3-6) UNRELEASED; urgency=medium - allows use of register in udev to avoid "device_busy" error. - prevent crash on changing writeback_running - Change refill_dirty() to always scan entire disk if necessary + * KEYS: Fix keyring ref leak in join_session_keyring() (CVE-2016-0728) [ Salvatore Bonaccorso ] * unix: properly account for FDs passed over unix sockets (CVE-2013-4312) diff --git a/debian/patches/bugfix/all/KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch b/debian/patches/bugfix/all/KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch new file mode 100644 index 000000000000..9c6a9697387d --- /dev/null +++ b/debian/patches/bugfix/all/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 + diff --git a/debian/patches/series b/debian/patches/series index 70ca0b08f6d8..82ac5d4c973b 100644 --- a/debian/patches/series +++ b/debian/patches/series @@ -147,3 +147,4 @@ bugfix/all/bcache-unregister-reboot-notifier-if-bcache-fails-to.patch bugfix/all/bcache-allows-use-of-register-in-udev-to-avoid-devic.patch bugfix/all/bcache-prevent-crash-on-changing-writeback_running.patch bugfix/all/bcache-change-refill_dirty-to-always-scan-entire-dis.patch +bugfix/all/KEYS-Fix-keyring-ref-leak-in-join_session_keyring.patch |