From a9e01ac8c5ff32669119c40dfdc9e80eb0b7d7aa Mon Sep 17 00:00:00 2001 From: David Howells Date: Thu, 21 Dec 2023 15:09:31 +0000 Subject: [PATCH] afs: Fix overwriting of result of DNS query In afs_update_cell(), ret is the result of the DNS lookup and the errors are to be handled by a switch - however, the value gets clobbered in between by setting it to -ENOMEM in case afs_alloc_vlserver_list() fails. Fix this by moving the setting of -ENOMEM into the error handling for OOM failure. Further, only do it if we don't have an alternative error to return. Found by Linux Verification Center (linuxtesting.org) with SVACE. Based on a patch from Anastasia Belova [1]. Fixes: d5c32c89b208 ("afs: Fix cell DNS lookup") Signed-off-by: David Howells Reviewed-by: Jeffrey Altman cc: Anastasia Belova cc: Marc Dionne cc: linux-afs@lists.infradead.org cc: lvc-project@linuxtesting.org Link: https://lore.kernel.org/r/20231221085849.1463-1-abelova@astralinux.ru/ [1] Link: https://lore.kernel.org/r/1700862.1703168632@warthog.procyon.org.uk/ # v1 Signed-off-by: Linus Torvalds --- fs/afs/cell.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/fs/afs/cell.c b/fs/afs/cell.c index 988c2ac7cece..926cb1188eba 100644 --- a/fs/afs/cell.c +++ b/fs/afs/cell.c @@ -409,10 +409,12 @@ static int afs_update_cell(struct afs_cell *cell) if (ret == -ENOMEM) goto out_wake; - ret = -ENOMEM; vllist = afs_alloc_vlserver_list(0); - if (!vllist) + if (!vllist) { + if (ret >= 0) + ret = -ENOMEM; goto out_wake; + } switch (ret) { case -ENODATA: