diff options
author | Miklos Szeredi <mszeredi@redhat.com> | 2019-01-16 10:27:59 +0100 |
---|---|---|
committer | Ben Hutchings <ben@decadent.org.uk> | 2019-05-02 21:41:22 +0100 |
commit | 2e1f7654f16212bffab18033f9bf95cdca1764e5 (patch) | |
tree | 31f3281adaf1fe82f54a345bafef305b0b650619 /fs | |
parent | 90451cdfd921c1e550fa25c155279427510db063 (diff) |
fuse: handle zero sized retrieve correctly
commit 97e1532ef81acb31c30f9e75bf00306c33a77812 upstream.
Dereferencing req->page_descs[0] will Oops if req->max_pages is zero.
Reported-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Tested-by: syzbot+c1e36d30ee3416289cc0@syzkaller.appspotmail.com
Fixes: b2430d7567a3 ("fuse: add per-page descriptor <offset, length> to fuse_req")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'fs')
-rw-r--r-- | fs/fuse/dev.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index db2963a54f16..df1dfc4d535e 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1652,7 +1652,6 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, req->in.h.nodeid = outarg->nodeid; req->in.numargs = 2; req->in.argpages = 1; - req->page_descs[0].offset = offset; req->end = fuse_retrieve_end; index = outarg->offset >> PAGE_CACHE_SHIFT; @@ -1667,6 +1666,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset); req->pages[req->num_pages] = page; + req->page_descs[req->num_pages].offset = offset; req->page_descs[req->num_pages].length = this_num; req->num_pages++; |