Neil Brown: Fix for segfault when reading /proc/mdstat

[Martin F. Krafft]

Module: mdadm
Branch: build
Commit: 2cdb64897d4fe33a11af13c6356dcd338c561e77
URL:    http://git.debian.org/?p=pkg-mdadm/mdadm.git;a=commit;h=2cdb64897d4fe33a11af13c6356dcd338c561e77

Author: Neil Brown <neilb at suse.de>
Date:   Mon Apr 28 16:29:12 2008 +1000

Fix for segfault when reading /proc/mdstat

Some kernel versions don't put a space between 'active' and '(auto-read-only)'
in /proc/mdstat.  This causes a parsing problem leaving 'level' set to
NULL which causes a crash.

So synthesise a space there if it is missing, and check for 'level' to
be NULL and don't de-ref if it is.

---

 ChangeLog     |    4 ++++
 Incremental.c |    1 +
 Monitor.c     |    1 +
 config.c      |   13 +++++++++++++
 4 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index fa4fed4..fdf720d 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,7 @@
+Changes Prior to this release
+    -   Avoid segfault when parsing /proc/mdstat with auto-read-only
+	arrays.
+
 Changes Prior to 2.6.4 release
     -   Make "--create --auto=mdp" work for non-standard device names.
     -   Fix restarting of a 'reshape' if it was stopped in the middle.
diff --git a/Incremental.c b/Incremental.c
index ab37ef0..4c6a2a7 100644
--- a/Incremental.c
+++ b/Incremental.c
@@ -332,6 +332,7 @@ int Incremental(char *devname, int verbose, int runstop,
 		struct supertype *st2;
 		sra = sysfs_read(mdfd, devnum, (GET_VERSION | GET_DEVS |
 						GET_STATE));
+
 		if (sra->array.major_version != st->ss->major ||
 		    sra->array.minor_version != st->minor_version) {
 			if (verbose >= 0)
diff --git a/Monitor.c b/Monitor.c
index 6b0c760..54193f5 100644
--- a/Monitor.c
+++ b/Monitor.c
@@ -403,6 +403,7 @@ int Monitor(mddev_dev_t devlist,
 			struct mdstat_ent *mse;
 			for (mse=mdstat; mse; mse=mse->next)
 				if (mse->devnum != INT_MAX &&
+				    mse->level &&
 				    (strcmp(mse->level, "raid0")!=0 &&
 				     strcmp(mse->level, "linear")!=0)
 					) {
diff --git a/config.c b/config.c
index 29eadc5..121b337 100644
--- a/config.c
+++ b/config.c
@@ -161,11 +161,24 @@ char *conf_word(FILE *file, int allow_key)
 					word[len++] = c;
 				}
 				c = getc(file);
+				/* Hack for broken kernels (2.6.14-.24) that put
+				 *        "active(auto-read-only)"
+				 * in /proc/mdstat instead of
+				 *        "active (auto-read-only)"
+				 */
+				if (c == '(' && len >= 6
+				    && strncmp(word+len-6, "active", 6) == 0)
+					c = ' ';
 			}
 		}
 		if (c != EOF) ungetc(c, file);
 	}
 	word[len] = 0;
+
+	/* Further HACK for broken kernels.. 2.6.14-2.6.24 */
+	if (strcmp(word, "auto-read-only)") == 0)
+		strcpy(word, "(auto-read-only)");
+
 /*    printf("word is <%s>\n", word); */
 	if (!wordfound) {
 		free(word);