[ Upstream commit 2803cf4379ed252894f046cb8812a48db35294e3 ]
v9fs_dir_readdir() could deadloop if a struct was sent with a size set to -2
Link: http://lkml.kernel.org/r/1536134432-11997-1-git-send-email-asmadeus@codewrec... Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=88021 Signed-off-by: Gertjan Halkes gertjan@google.com Signed-off-by: Dominique Martinet dominique.martinet@cea.fr Signed-off-by: Sasha Levin sashal@kernel.org --- fs/9p/vfs_dir.c | 8 +++----- net/9p/protocol.c | 3 ++- 2 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/fs/9p/vfs_dir.c b/fs/9p/vfs_dir.c index cfe4cf6486af..fa7d1c3536e6 100644 --- a/fs/9p/vfs_dir.c +++ b/fs/9p/vfs_dir.c @@ -104,7 +104,6 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) int err = 0; struct p9_fid *fid; int buflen; - int reclen = 0; struct p9_rdir *rdir;
p9_debug(P9_DEBUG_VFS, "name %pD\n", file); @@ -129,11 +128,10 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) while (rdir->head < rdir->tail) { err = p9stat_read(fid->clnt, rdir->buf + rdir->head, rdir->tail - rdir->head, &st); - if (err) { + if (err <= 0) { p9_debug(P9_DEBUG_VFS, "returned %d\n", err); return -EIO; } - reclen = st.size+2;
over = !dir_emit(ctx, st.name, strlen(st.name), v9fs_qid2ino(&st.qid), dt_type(&st)); @@ -141,8 +139,8 @@ static int v9fs_dir_readdir(struct file *file, struct dir_context *ctx) if (over) return 0;
- rdir->head += reclen; - ctx->pos += reclen; + rdir->head += err; + ctx->pos += err; } } } diff --git a/net/9p/protocol.c b/net/9p/protocol.c index bceb6999614f..66613837b287 100644 --- a/net/9p/protocol.c +++ b/net/9p/protocol.c @@ -578,9 +578,10 @@ int p9stat_read(struct p9_client *clnt, char *buf, int len, struct p9_wstat *st) if (ret) { p9_debug(P9_DEBUG_9P, "<<< p9stat_read failed: %d\n", ret); trace_9p_protocol_dump(clnt, &fake_pdu); + return ret; }
- return ret; + return fake_pdu.offset; } EXPORT_SYMBOL(p9stat_read);