diff options
| author | Bernd Schubert <bschubert@ddn.com> | 2024-12-03 00:01:10 +0100 |
|---|---|---|
| committer | Miklos Szeredi <mszeredi@redhat.com> | 2024-12-13 16:43:36 +0100 |
| commit | 78f2560fc9fa5ccaaf23ac78edb732c08bad7a92 (patch) | |
| tree | af3e4c412a53917c22e19fade73ac88109cc0216 | |
| parent | fuse: fix direct io folio offset and length calculation (diff) | |
| download | linux-78f2560fc9fa5ccaaf23ac78edb732c08bad7a92.tar.xz linux-78f2560fc9fa5ccaaf23ac78edb732c08bad7a92.zip | |
fuse: Set *nbytesp=0 in fuse_get_user_pages on allocation failure
In fuse_get_user_pages(), set *nbytesp to 0 when struct page **pages
allocation fails. This prevents the caller (fuse_direct_io) from making
incorrect assumptions that could lead to NULL pointer dereferences
when processing the request reply.
Previously, *nbytesp was left unmodified on allocation failure, which
could cause issues if the caller assumed pages had been added to
ap->descs[] when they hadn't.
Reported-by: syzbot+87b8e6ed25dbc41759f7@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=87b8e6ed25dbc41759f7
Fixes: 3b97c3652d91 ("fuse: convert direct io to use folios")
Signed-off-by: Bernd Schubert <bschubert@ddn.com>
Reviewed-by: Joanne Koong <joannelkoong@gmail.com>
Tested-by: Dmitry Antipov <dmantipov@yandex.ru>
Tested-by: David Howells <dhowells@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| -rw-r--r-- | fs/fuse/file.c | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 15b08d6a5739..7d92a5479998 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1541,8 +1541,10 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii, */ struct page **pages = kzalloc(max_pages * sizeof(struct page *), GFP_KERNEL); - if (!pages) - return -ENOMEM; + if (!pages) { + ret = -ENOMEM; + goto out; + } while (nbytes < *nbytesp && nr_pages < max_pages) { unsigned nfolios, i; @@ -1588,6 +1590,7 @@ static int fuse_get_user_pages(struct fuse_args_pages *ap, struct iov_iter *ii, else ap->args.out_pages = true; +out: *nbytesp = nbytes; return ret < 0 ? ret : 0; |