From 8e5179f982f94a28dc661adcc1d8a6a50c6a7537 Mon Sep 17 00:00:00 2001 From: Marc Dionne Date: Tue, 30 Jul 2019 14:38:51 +0100 Subject: [PATCH] afs: Fix loop index mixup in afs_deliver_vl_get_entry_by_name_u() [ Upstream commit 4a46fdba449a5cd890271df5a9e23927d519ed00 ] afs_deliver_vl_get_entry_by_name_u() scans through the vl entry received from the volume location server and builds a return list containing the sites that are currently valid. When assigning values for the return list, the index into the vl entry (i) is used rather than the one for the new list (entry->nr_server). If all sites are usable, this works out fine as the indices will match. If some sites are not valid, for example if AFS_VLSF_DONTUSE is set, fs_mask and the uuid will be set for the wrong return site. Fix this by using entry->nr_server as the index into the arrays being filled in rather than i. This can lead to EDESTADDRREQ errors if none of the returned sites have a valid fs_mask. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: Marc Dionne Signed-off-by: David Howells Reviewed-by: Jeffrey Altman Signed-off-by: Sasha Levin --- fs/afs/vlclient.c | 11 ++++++----- 1 file changed, 6 insertions(+), 5 deletions(-) diff --git a/fs/afs/vlclient.c b/fs/afs/vlclient.c index c3b7408..c7dd47e 100644 --- a/fs/afs/vlclient.c +++ b/fs/afs/vlclient.c @@ -60,23 +60,24 @@ static int afs_deliver_vl_get_entry_by_name_u(struct afs_call *call) struct afs_uuid__xdr *xdr; struct afs_uuid *uuid; int j; + int n = entry->nr_servers; tmp = ntohl(uvldb->serverFlags[i]); if (tmp & AFS_VLSF_DONTUSE || (new_only && !(tmp & AFS_VLSF_NEWREPSITE))) continue; if (tmp & AFS_VLSF_RWVOL) { - entry->fs_mask[i] |= AFS_VOL_VTM_RW; + entry->fs_mask[n] |= AFS_VOL_VTM_RW; if (vlflags & AFS_VLF_BACKEXISTS) - entry->fs_mask[i] |= AFS_VOL_VTM_BAK; + entry->fs_mask[n] |= AFS_VOL_VTM_BAK; } if (tmp & AFS_VLSF_ROVOL) - entry->fs_mask[i] |= AFS_VOL_VTM_RO; - if (!entry->fs_mask[i]) + entry->fs_mask[n] |= AFS_VOL_VTM_RO; + if (!entry->fs_mask[n]) continue; xdr = &uvldb->serverNumber[i]; - uuid = (struct afs_uuid *)&entry->fs_server[i]; + uuid = (struct afs_uuid *)&entry->fs_server[n]; uuid->time_low = xdr->time_low; uuid->time_mid = htons(ntohl(xdr->time_mid)); uuid->time_hi_and_version = htons(ntohl(xdr->time_hi_and_version)); -- 2.7.4