From ef65498c8087bfe87bec01299b30ae7d683d1ccd Mon Sep 17 00:00:00 2001 From: Fedor Pchelkin Date: Tue, 25 Jul 2023 14:59:30 +0300 Subject: [PATCH] NFSv4: fix out path in __nfs4_get_acl_uncached [ Upstream commit f4e89f1a6dab4c063fc1e823cc9dddc408ff40cf ] Another highly rare error case when a page allocating loop (inside __nfs4_get_acl_uncached, this time) is not properly unwound on error. Since pages array is allocated being uninitialized, need to free only lower array indices. NULL checks were useful before commit 62a1573fcf84 ("NFSv4 fix acl retrieval over krb5i/krb5p mounts") when the array had been initialized to zero on stack. Found by Linux Verification Center (linuxtesting.org). Fixes: 62a1573fcf84 ("NFSv4 fix acl retrieval over krb5i/krb5p mounts") Signed-off-by: Fedor Pchelkin Reviewed-by: Benjamin Coddington Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- fs/nfs/nfs4proc.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 9faba2dac11dd..f16742b8e0e21 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -6004,9 +6004,8 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, out_ok: ret = res.acl_len; out_free: - for (i = 0; i < npages; i++) - if (pages[i]) - __free_page(pages[i]); + while (--i >= 0) + __free_page(pages[i]); if (res.acl_scratch) __free_page(res.acl_scratch); kfree(pages); -- 2.47.2