This is a note to let you know that I've just added the patch titled NFSv4: fix getacl ERANGE for some ACL buffer sizes to the 4.4-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: nfsv4-fix-getacl-erange-for-some-acl-buffer-sizes.patch and it can be found in the queue-4.4 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From ed92d8c137b7794c2c2aa14479298b9885967607 Mon Sep 17 00:00:00 2001 From: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> Date: Thu, 23 Feb 2017 14:54:21 -0500 Subject: NFSv4: fix getacl ERANGE for some ACL buffer sizes From: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> commit ed92d8c137b7794c2c2aa14479298b9885967607 upstream. We're not taking into account that the space needed for the (variable length) attr bitmap, with the result that we'd sometimes get a spurious ERANGE when the ACL data got close to the end of a page. Just add in an extra page to make sure. Signed-off-by: Weston Andros Adamson <dros@xxxxxxxxxxxxxxx> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx> Signed-off-by: Anna Schumaker <Anna.Schumaker@xxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- fs/nfs/nfs4proc.c | 8 ++------ 1 file changed, 2 insertions(+), 6 deletions(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -4711,7 +4711,7 @@ out: */ static ssize_t __nfs4_get_acl_uncached(struct inode *inode, void *buf, size_t buflen) { - struct page *pages[NFS4ACL_MAXPAGES] = {NULL, }; + struct page *pages[NFS4ACL_MAXPAGES + 1] = {NULL, }; struct nfs_getaclargs args = { .fh = NFS_FH(inode), .acl_pages = pages, @@ -4725,13 +4725,9 @@ static ssize_t __nfs4_get_acl_uncached(s .rpc_argp = &args, .rpc_resp = &res, }; - unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE); + unsigned int npages = DIV_ROUND_UP(buflen, PAGE_SIZE) + 1; int ret = -ENOMEM, i; - /* As long as we're doing a round trip to the server anyway, - * let's be prepared for a page of acl data. */ - if (npages == 0) - npages = 1; if (npages > ARRAY_SIZE(pages)) return -ERANGE; Patches currently in stable-queue which might be from dros@xxxxxxxxxxxxxxx are queue-4.4/nfsv4-fix-getacl-erange-for-some-acl-buffer-sizes.patch