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| author | Miklos Szeredi <mszeredi@redhat.com> | 2019-01-16 10:27:59 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-02-12 19:46:11 +0100 |
| commit | 266a69895b89b8dd5f7501cd3de07fb935a1862c (patch) | |
| tree | c9b47d06d7c804f524c3f7303bf6edbc6c993f7f /fs | |
| parent | b928e93d864ccaa136e3e75959385291b8bb0880 (diff) | |
| download | linux-exynos-266a69895b89b8dd5f7501cd3de07fb935a1862c.tar.gz linux-exynos-266a69895b89b8dd5f7501cd3de07fb935a1862c.tar.bz2 linux-exynos-266a69895b89b8dd5f7501cd3de07fb935a1862c.zip | |
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")
Cc: <stable@vger.kernel.org> # v3.9
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 b29861854de4..63fd33383413 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -1691,7 +1691,6 @@ 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_SHIFT; @@ -1706,6 +1705,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode, this_num = min_t(unsigned, num, PAGE_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++; |