5.15-stable review patch. If anyone has any objections, please let me know.
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From: Fedor Pchelkin pchelkin@ispras.ru
[ 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 pchelkin@ispras.ru Reviewed-by: Benjamin Coddington bcodding@redhat.com Signed-off-by: Trond Myklebust trond.myklebust@hammerspace.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 b1ec9b5d06e58..31bf3e9dc7a56 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -5964,9 +5964,8 @@ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t bu 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);