afs: Fix overwriting of result of DNS query

[ Upstream commit a9e01ac8c5ff32669119c40dfdc9e80eb0b7d7aa ]

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: d5c32c89b2 ("afs: Fix cell DNS lookup")
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeffrey Altman <jaltman@auristor.com>
cc: Anastasia Belova <abelova@astralinux.ru>
cc: Marc Dionne <marc.dionne@auristor.com>
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 <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
David Howells 2023-12-21 15:09:31 +00:00 committed by Greg Kroah-Hartman
parent c04b7b28c9
commit 47ae524229

View File

@ -404,10 +404,12 @@ static int afs_update_cell(struct afs_cell *cell)
if (ret == -ENOMEM) if (ret == -ENOMEM)
goto out_wake; goto out_wake;
ret = -ENOMEM;
vllist = afs_alloc_vlserver_list(0); vllist = afs_alloc_vlserver_list(0);
if (!vllist) if (!vllist) {
if (ret >= 0)
ret = -ENOMEM;
goto out_wake; goto out_wake;
}
switch (ret) { switch (ret) {
case -ENODATA: case -ENODATA: