apparmor: fix off-by-one comparison on MAXMAPPED_SIG
This came in yesterday, and I have verified our regression tests
were missing this and it can cause an oops. Please apply.
There is a an off-by-one comparision on sig against MAXMAPPED_SIG
that can lead to a read outside the sig_map array if sig
is MAXMAPPED_SIG. Fix this.
Verified that the check is an out of bounds case that can cause an oops.
Revised: add comparison fix to second case
Fixes: cd1dbf76b23d ("apparmor: add the ability to mediate signals")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/security/apparmor/ipc.c b/security/apparmor/ipc.c
index 66fb9ed..7ca0032 100644
--- a/security/apparmor/ipc.c
+++ b/security/apparmor/ipc.c
@@ -128,7 +128,7 @@
return SIGUNKNOWN;
else if (sig >= SIGRTMIN)
return sig - SIGRTMIN + 128; /* rt sigs mapped to 128 */
- else if (sig <= MAXMAPPED_SIG)
+ else if (sig < MAXMAPPED_SIG)
return sig_map[sig];
return SIGUNKNOWN;
}
@@ -163,7 +163,7 @@
audit_signal_mask(ab, aad(sa)->denied);
}
}
- if (aad(sa)->signal <= MAXMAPPED_SIG)
+ if (aad(sa)->signal < MAXMAPPED_SIG)
audit_log_format(ab, " signal=%s", sig_names[aad(sa)->signal]);
else
audit_log_format(ab, " signal=rtmin+%d",
