From b119f0178fd86876d0678007dfcf435ab8bb7568 Mon Sep 17 00:00:00 2001 From: Juergen Gross Date: Wed, 7 Feb 2024 13:52:13 +0100 Subject: [PATCH] Mini-OS: fix 9pfs frontend error path The early error exit in p9_stat() returns without zeroing the p9_stat buffer, resulting in free() being called with an uninitialized pointer. Fix that by calling free_stat() in p9_stat() in case of returning an error and potentially having allocated strings. Reported-by: Julien Grall Fixes: 2d1dfccd3aa3 ("Mini-OS: add read and write support to 9pfsfront") Signed-off-by: Juergen Gross Reviewed-by: Samuel Thibault --- 9pfront.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/9pfront.c b/9pfront.c index 315089b..042879a 100644 --- a/9pfront.c +++ b/9pfront.c @@ -728,6 +728,8 @@ static int p9_stat(struct dev_9pfs *dev, uint32_t fid, struct p9_stat *stat) &stat->extension, &stat->n_uid, &stat->n_gid, &stat->n_muid); ret = req->result; + if ( ret ) + free_stat(&stat); put_free_req(dev, req); @@ -932,13 +934,13 @@ static int write_9pfs(struct file *file, const void *buf, size_t nbytes) if ( f9pfs->append ) { ret = p9_stat(f9pfs->dev, f9pfs->fid, &stat); - free_stat(&stat); if ( ret ) { errno = EIO; return -1; } file->offset = stat.length; + free_stat(&stat); } ret = p9_write(f9pfs->dev, f9pfs->fid, file->offset, buf, nbytes); -- 2.39.5