This is a note to let you know that I've just added the patch titled auditsc: audit_krule mask accesses need bounds checking to the 3.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: auditsc-audit_krule-mask-accesses-need-bounds-checking.patch and it can be found in the queue-3.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a3c54931199565930d6d84f4c3456f6440aefd41 Mon Sep 17 00:00:00 2001 From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Date: Wed, 28 May 2014 23:09:58 -0400 Subject: auditsc: audit_krule mask accesses need bounds checking From: Andy Lutomirski <luto@xxxxxxxxxxxxxx> commit a3c54931199565930d6d84f4c3456f6440aefd41 upstream. Fixes an easy DoS and possible information disclosure. This does nothing about the broken state of x32 auditing. eparis: If the admin has enabled auditd and has specifically loaded audit rules. This bug has been around since before git. Wow... Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx> Signed-off-by: Eric Paris <eparis@xxxxxxxxxx> Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- kernel/auditsc.c | 27 ++++++++++++++++++--------- 1 file changed, 18 insertions(+), 9 deletions(-) --- a/kernel/auditsc.c +++ b/kernel/auditsc.c @@ -728,6 +728,22 @@ static enum audit_state audit_filter_tas return AUDIT_BUILD_CONTEXT; } +static int audit_in_mask(const struct audit_krule *rule, unsigned long val) +{ + int word, bit; + + if (val > 0xffffffff) + return false; + + word = AUDIT_WORD(val); + if (word >= AUDIT_BITMASK_SIZE) + return false; + + bit = AUDIT_BIT(val); + + return rule->mask[word] & bit; +} + /* At syscall entry and exit time, this filter is called if the * audit_state is not low enough that auditing cannot take place, but is * also not high enough that we already know we have to write an audit @@ -745,11 +761,8 @@ static enum audit_state audit_filter_sys rcu_read_lock(); if (!list_empty(list)) { - int word = AUDIT_WORD(ctx->major); - int bit = AUDIT_BIT(ctx->major); - list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, NULL, &state, false)) { rcu_read_unlock(); @@ -769,20 +782,16 @@ static enum audit_state audit_filter_sys static int audit_filter_inode_name(struct task_struct *tsk, struct audit_names *n, struct audit_context *ctx) { - int word, bit; int h = audit_hash_ino((u32)n->ino); struct list_head *list = &audit_inode_hash[h]; struct audit_entry *e; enum audit_state state; - word = AUDIT_WORD(ctx->major); - bit = AUDIT_BIT(ctx->major); - if (list_empty(list)) return 0; list_for_each_entry_rcu(e, list, list) { - if ((e->rule.mask[word] & bit) == bit && + if (audit_in_mask(&e->rule, ctx->major) && audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) { ctx->current_state = state; return 1; Patches currently in stable-queue which might be from luto@xxxxxxxxxxxxxx are queue-3.15/fs-userns-change-inode_capable-to-capable_wrt_inode_uidgid.patch queue-3.15/auditsc-audit_krule-mask-accesses-need-bounds-checking.patch -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html