From: Martin Wilck <mwi...@suse.de> LOG_MSG() will dereference pp->mpp. Commit cb5ec664 added a call to LOG_MSG() before the check for (!pp->mpp) in check_path. This can cause multipathd to crash. LOG_MSG() should check the fields before dereferencing them. Make checker_selected() an inline function to allow the compiler to optimize away the usually redundant test "if (&checker->pp != NULL)".
Also, checker_message() should fail to a generic message if c->cls isn't set (which means that a checker hasn't been selected). Fixes: cb5ec664 (multipathd: check_path: improve logging for "unusable path" case) Signed-off-by: Benjamin Marzinski <bmarz...@redhat.com> Signed-off-by: Martin Wilck <mwi...@suse.com> --- libmultipath/checkers.c | 9 +-------- libmultipath/checkers.h | 6 +++++- multipathd/main.c | 6 ++++-- 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/libmultipath/checkers.c b/libmultipath/checkers.c index 848c4c3..f4fdcae 100644 --- a/libmultipath/checkers.c +++ b/libmultipath/checkers.c @@ -261,13 +261,6 @@ int checker_check (struct checker * c, int path_state) return r; } -int checker_selected(const struct checker *c) -{ - if (!c) - return 0; - return c->cls != NULL; -} - const char *checker_name(const struct checker *c) { if (!c || !c->cls) @@ -295,7 +288,7 @@ const char *checker_message(const struct checker *c) { int id; - if (!c || c->msgid < 0 || + if (!c || !c->cls || c->msgid < 0 || (c->msgid >= CHECKER_GENERIC_MSGTABLE_SIZE && c->msgid < CHECKER_FIRST_MSGID)) goto bad_id; diff --git a/libmultipath/checkers.h b/libmultipath/checkers.h index b2e8f9a..dab197f 100644 --- a/libmultipath/checkers.h +++ b/libmultipath/checkers.h @@ -129,6 +129,11 @@ struct checker { you want to stuff data in. */ }; +static inline int checker_selected(const struct checker *c) +{ + return c != NULL && c->cls != NULL; +} + const char *checker_state_name(int); int init_checkers(const char *); void cleanup_checkers (void); @@ -142,7 +147,6 @@ void checker_set_fd (struct checker *, int); void checker_enable (struct checker *); void checker_disable (struct checker *); int checker_check (struct checker *, int); -int checker_selected(const struct checker *); int checker_is_sync(const struct checker *); const char *checker_name (const struct checker *); /* diff --git a/multipathd/main.c b/multipathd/main.c index 0e3ac2c..37bea63 100644 --- a/multipathd/main.c +++ b/multipathd/main.c @@ -92,7 +92,8 @@ static int use_watchdog; #define LOG_MSG(lvl, verb, pp) \ do { \ - if (lvl <= verb) { \ + if (pp->mpp && checker_selected(&pp->checker) && \ + lvl <= verb) { \ if (pp->offline) \ condlog(lvl, "%s: %s - path offline", \ pp->mpp->alias, pp->dev); \ @@ -2017,7 +2018,8 @@ check_path (struct vectors * vecs, struct path * pp, int ticks) } if (newstate == PATH_WILD || newstate == PATH_UNCHECKED) { - condlog(2, "%s: unusable path - checker failed", pp->dev); + condlog(2, "%s: unusable path (%s) - checker failed", + pp->dev, checker_state_name(newstate)); LOG_MSG(2, verbosity, pp); conf = get_multipath_config(); pthread_cleanup_push(put_multipath_config, conf); -- 2.17.2 -- dm-devel mailing list dm-devel@redhat.com https://www.redhat.com/mailman/listinfo/dm-devel