Fix bug where tdb lock call interrupted with

an alarm sig would not terminate and could lead
to runaway smbd processes.
Thanks to Dave Daugherty @ Centrify for pointing
this out to us.
Jeremy.
(This used to be commit ef8da1698371c95495add53df81a978df709c88d)

2 files changed, 14 insertions, 0 deletions

diff --git a/source3/lib/tdb/common/lock.c b/source3/lib/tdb/common/lock.c
index 22896f5227..43be5d20e1 100644
--- a/source3/lib/tdb/common/lock.c
+++ b/source3/lib/tdb/common/lock.c
@@ -27,6 +27,11 @@
 
 #include "tdb_private.h"
 
+void tdb_setalarm_sigptr(struct tdb_context *tdb, volatile sig_atomic_t *ptr)
+{
+	tdb->interrupt_sig_ptr = ptr;
+}
+
 /* a byte range locking function - return 0 on success
    this functions locks/unlocks 1 byte at the specified offset.
 
@@ -58,6 +63,13 @@ int tdb_brlock(struct tdb_context *tdb, tdb_off_t offset,
 
 	do {
 		ret = fcntl(tdb->fd,lck_type,&fl);
+
+		/* Check for a sigalarm break. */
+		if (ret == -1 && errno == EINTR &&
+				tdb->interrupt_sig_ptr &&
+				*tdb->interrupt_sig_ptr) {
+			break;
+		}
 	} while (ret == -1 && errno == EINTR);
 
 	if (ret == -1) {
diff --git a/source3/lib/tdb/common/tdb_private.h b/source3/lib/tdb/common/tdb_private.h
index d2f2c23d72..daef07aff1 100644
--- a/source3/lib/tdb/common/tdb_private.h
+++ b/source3/lib/tdb/common/tdb_private.h
@@ -28,6 +28,7 @@
 #include "system/time.h"
 #include "system/shmem.h"
 #include "system/select.h"
+#include "system/wait.h"
 #include "tdb.h"
 
 #ifndef HAVE_GETPAGESIZE
@@ -161,6 +162,7 @@ struct tdb_context {
 	struct tdb_transaction *transaction;
 	int page_size;
 	int max_dead_records;
+	volatile sig_atomic_t *interrupt_sig_ptr;
 };