From: David Howells <dhowells@redhat.com>
To: viro@zeniv.linux.org.uk
Cc: Miklos Szeredi <mszeredi@redhat.com>,
dhowells@redhat.com, torvalds@linux-foundation.org,
casey@schaufler-ca.com, sds@tycho.nsa.gov,
nicolas.dichtel@6wind.com, raven@themaw.net,
christian@brauner.io, jlayton@redhat.com, kzak@redhat.com,
mszeredi@redhat.com, linux-api@vger.kernel.org,
linux-fsdevel@vger.kernel.org,
linux-security-module@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: [PATCH 1/4] watch_queue: Make watch_sizeof() check record size
Date: Fri, 24 Jul 2020 14:11:31 +0100 [thread overview]
Message-ID: <159559629177.2141315.10412134789878021738.stgit@warthog.procyon.org.uk> (raw)
In-Reply-To: <159559628247.2141315.2107013106060144287.stgit@warthog.procyon.org.uk>
Make watch_sizeof() give a build error if the size of the struct won't fit
into the size field in the header.
Reported-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: David Howells <dhowells@redhat.com>
---
include/linux/watch_queue.h | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)
diff --git a/include/linux/watch_queue.h b/include/linux/watch_queue.h
index 5e08db2adc31..38e04c7a7951 100644
--- a/include/linux/watch_queue.h
+++ b/include/linux/watch_queue.h
@@ -120,7 +120,12 @@ static inline void remove_watch_list(struct watch_list *wlist, u64 id)
* watch_sizeof - Calculate the information part of the size of a watch record,
* given the structure size.
*/
-#define watch_sizeof(STRUCT) (sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT)
+#define watch_sizeof(STRUCT) \
+ ({ \
+ size_t max = WATCH_INFO_LENGTH >> WATCH_INFO_LENGTH__SHIFT; \
+ BUILD_BUG_ON(sizeof(STRUCT) > max); \
+ sizeof(STRUCT) << WATCH_INFO_LENGTH__SHIFT; \
+ })
#endif
next prev parent reply other threads:[~2020-07-24 13:11 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-24 13:11 [PATCH 0/4] Mount notifications David Howells
2020-07-24 13:11 ` David Howells [this message]
2020-07-24 13:11 ` [PATCH 2/4] watch_queue: Add security hooks to rule on setting mount watches David Howells
2020-07-24 13:11 ` [PATCH 3/4] watch_queue: Implement mount topology and attribute change notifications David Howells
2020-07-24 19:14 ` Linus Torvalds
2020-07-24 19:59 ` David Howells
2020-07-24 20:25 ` Linus Torvalds
2020-07-24 20:45 ` David Howells
2020-07-24 13:11 ` [PATCH 4/4] watch_queue: sample: Display mount tree " David Howells
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