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| author | Gabriel Krisman Bertazi <krisman@collabora.com> | 2021-10-25 22:27:40 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2024-06-21 15:53:24 +0300 |
| commit | bb247feb22d76161d28d67d80da06c6ca459fd34 (patch) | |
| tree | 4d8e11593b056e95f6daa121e7a74428c7f3b0a5 /fs/notify | |
| parent | 7fa20568b6e5150ce6ccf437769a92a8144fd407 (diff) | |
| download | linux-bb247feb22d76161d28d67d80da06c6ca459fd34.tar.xz | |
fanotify: WARN_ON against too large file handles
[ Upstream commit 572c28f27a269f88e2d8d7b6b1507f114d637337 ]
struct fanotify_error_event, at least, is preallocated and isn't able to
to handle arbitrarily large file handles. Future-proof the code by
complaining loudly if a handle larger than MAX_HANDLE_SZ is ever found.
Link: https://lore.kernel.org/r/20211025192746.66445-26-krisman@collabora.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/notify')
| -rw-r--r-- | fs/notify/fanotify/fanotify.c | 12 |
1 files changed, 11 insertions, 1 deletions
diff --git a/fs/notify/fanotify/fanotify.c b/fs/notify/fanotify/fanotify.c index cedcb1546804..45df610debbe 100644 --- a/fs/notify/fanotify/fanotify.c +++ b/fs/notify/fanotify/fanotify.c @@ -360,13 +360,23 @@ static u32 fanotify_group_event_mask(struct fsnotify_group *group, static int fanotify_encode_fh_len(struct inode *inode) { int dwords = 0; + int fh_len; if (!inode) return 0; exportfs_encode_inode_fh(inode, NULL, &dwords, NULL); + fh_len = dwords << 2; - return dwords << 2; + /* + * struct fanotify_error_event might be preallocated and is + * limited to MAX_HANDLE_SZ. This should never happen, but + * safeguard by forcing an invalid file handle. + */ + if (WARN_ON_ONCE(fh_len > MAX_HANDLE_SZ)) + return 0; + + return fh_len; } /* |