81 lines
2.5 KiB
Diff
81 lines
2.5 KiB
Diff
From: Andy Lutomirski <luto@amacapital.net>
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Date: Wed, 28 May 2014 23:09:58 -0400
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Subject: auditsc: audit_krule mask accesses need bounds checking
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Origin: https://git.kernel.org/linus/a3c54931199565930d6d84f4c3456f6440aefd41
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Fixes an easy DoS and possible information disclosure.
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This does nothing about the broken state of x32 auditing.
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eparis: If the admin has enabled auditd and has specifically loaded
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audit rules. This bug has been around since before git. Wow...
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Cc: stable@vger.kernel.org
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Signed-off-by: Andy Lutomirski <luto@amacapital.net>
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Signed-off-by: Eric Paris <eparis@redhat.com>
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Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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---
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kernel/auditsc.c | 27 ++++++++++++++++++---------
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1 file changed, 18 insertions(+), 9 deletions(-)
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--- a/kernel/auditsc.c
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+++ b/kernel/auditsc.c
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@@ -720,6 +720,22 @@ static enum audit_state audit_filter_tas
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return AUDIT_BUILD_CONTEXT;
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}
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+static int audit_in_mask(const struct audit_krule *rule, unsigned long val)
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+{
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+ int word, bit;
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+
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+ if (val > 0xffffffff)
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+ return false;
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+
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+ word = AUDIT_WORD(val);
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+ if (word >= AUDIT_BITMASK_SIZE)
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+ return false;
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+
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+ bit = AUDIT_BIT(val);
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+
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+ return rule->mask[word] & bit;
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+}
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+
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/* At syscall entry and exit time, this filter is called if the
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* audit_state is not low enough that auditing cannot take place, but is
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* also not high enough that we already know we have to write an audit
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@@ -737,11 +753,8 @@ static enum audit_state audit_filter_sys
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rcu_read_lock();
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if (!list_empty(list)) {
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- int word = AUDIT_WORD(ctx->major);
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- int bit = AUDIT_BIT(ctx->major);
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-
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list_for_each_entry_rcu(e, list, list) {
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- if ((e->rule.mask[word] & bit) == bit &&
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+ if (audit_in_mask(&e->rule, ctx->major) &&
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audit_filter_rules(tsk, &e->rule, ctx, NULL,
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&state, false)) {
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rcu_read_unlock();
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@@ -761,20 +774,16 @@ static enum audit_state audit_filter_sys
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static int audit_filter_inode_name(struct task_struct *tsk,
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struct audit_names *n,
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struct audit_context *ctx) {
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- int word, bit;
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int h = audit_hash_ino((u32)n->ino);
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struct list_head *list = &audit_inode_hash[h];
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struct audit_entry *e;
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enum audit_state state;
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- word = AUDIT_WORD(ctx->major);
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- bit = AUDIT_BIT(ctx->major);
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-
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if (list_empty(list))
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return 0;
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list_for_each_entry_rcu(e, list, list) {
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- if ((e->rule.mask[word] & bit) == bit &&
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+ if (audit_in_mask(&e->rule, ctx->major) &&
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audit_filter_rules(tsk, &e->rule, ctx, n, &state, false)) {
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ctx->current_state = state;
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return 1;
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