diff mbox series

[4.9,44/49] xen-blkback: dont "handle" error by BUG()

Message ID	20210222121028.145787329@linuxfoundation.org
State	Superseded
Headers	show Return-Path: <stable-owner@kernel.org> From: Greg Kroah-Hartman <gregkh@linuxfoundation.org> To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>, stable@vger.kernel.org, Jan Beulich <jbeulich@suse.com>, Juergen Gross <jgross@suse.com> Subject: [PATCH 4.9 44/49] xen-blkback: dont "handle" error by BUG() Date: Mon, 22 Feb 2021 13:36:42 +0100 Message-Id: <20210222121028.145787329@linuxfoundation.org> In-Reply-To: <20210222121022.546148341@linuxfoundation.org> References: <20210222121022.546148341@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk
Series	None \| expand [4.9,02/49] fgraph: Initialize tracing_graph_pause at task creation [4.9,03/49] remoteproc: qcom_q6v5_mss: Validate MBA firmware size before load [4.9,04/49] af_key: relax availability checks for skb size calculation [4.9,05/49] iwlwifi: mvm: take mutex for calling iwl_mvm_get_sync_time() [4.9,06/49] iwlwifi: pcie: add a NULL check in iwl_pcie_txq_unmap [4.9,07/49] iwlwifi: mvm: guard against device removal in reprobe [4.9,08/49] SUNRPC: Move simple_get_bytes and simple_get_netobj into private header [4.9,09/49] SUNRPC: Handle 0 length opaque XDR object data properly [4.9,10/49] lib/string: Add strscpy_pad() function [4.9,11/49] include/trace/events/writeback.h: fix -Wstringop-truncation warnings [4.9,12/49] memcg: fix a crash in wb_workfn when a device disappears [4.9,13/49] futex: Ensure the correct return value from futex_lock_pi() [4.9,14/49] futex: Change locking rules [4.9,15/49] futex: Cure exit race [4.9,16/49] squashfs: add more sanity checks in id lookup [4.9,17/49] squashfs: add more sanity checks in inode lookup [4.9,18/49] squashfs: add more sanity checks in xattr id lookup [4.9,19/49] tracing: Do not count ftrace events in top level enable output [4.9,20/49] tracing: Check length before giving out the filter buffer [4.9,21/49] ovl: skip getxattr of security labels [4.9,22/49] ARM: dts: lpc32xx: Revert set default clock rate of HCLK PLL [4.9,23/49] memblock: do not start bottom-up allocations with kernel_end [4.9,24/49] bpf: Check for integer overflow when using roundup_pow_of_two() [4.9,25/49] netfilter: xt_recent: Fix attempt to update deleted entry [4.9,26/49] xen/netback: avoid race in xenvif_rx_ring_slots_available() [4.9,27/49] netfilter: conntrack: skip identical origin tuple in same zone only [4.9,28/49] h8300: fix PREEMPTION build, TI_PRE_COUNT undefined [4.9,29/49] usb: dwc3: ulpi: fix checkpatch warning [4.9,30/49] usb: dwc3: ulpi: Replace CPU-based busyloop with Protocol-based one [4.9,31/49] net/vmw_vsock: improve locking in vsock_connect_timeout() [4.9,32/49] net: watchdog: hold device global xmit lock during tx disable [4.9,33/49] vsock/virtio: update credit only if socket is not closed [4.9,34/49] vsock: fix locking in vsock_shutdown() [4.9,35/49] x86/build: Disable CET instrumentation in the kernel for 32-bit too [4.9,36/49] trace: Use -mcount-record for dynamic ftrace [4.9,37/49] tracing: Fix SKIP_STACK_VALIDATION=1 build due to bad merge with -mrecord-mcount [4.9,38/49] tracing: Avoid calling cc-option -mrecord-mcount for every Makefile [4.9,39/49] Xen/x86: dont bail early from clear_foreign_p2m_mapping() [4.9,40/49] Xen/x86: also check kernel mapping in set_foreign_p2m_mapping() [4.9,41/49] Xen/gntdev: correct dev_bus_addr handling in gntdev_map_grant_pages() [4.9,42/49] Xen/gntdev: correct error checking in gntdev_map_grant_pages() [4.9,43/49] xen/arm: dont ignore return errors from set_phys_to_machine [4.9,44/49] xen-blkback: dont "handle" error by BUG() [4.9,45/49] xen-netback: dont "handle" error by BUG() [4.9,46/49] xen-scsiback: dont "handle" error by BUG() [4.9,47/49] xen-blkback: fix error handling in xen_blkbk_map() [4.9,48/49] scsi: qla2xxx: Fix crash during driver load on big endian machines [4.9,49/49] kvm: check tlbs_dirty directly

Commit Message

Greg KH Feb. 22, 2021, 12:36 p.m. UTC

From: Jan Beulich <jbeulich@suse.com>

commit 5a264285ed1cd32e26d9de4f3c8c6855e467fd63 upstream.

In particular -ENOMEM may come back here, from set_foreign_p2m_mapping().
Don't make problems worse, the more that handling elsewhere (together
with map's status fields now indicating whether a mapping wasn't even
attempted, and hence has to be considered failed) doesn't require this
odd way of dealing with errors.

This is part of XSA-362.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: stable@vger.kernel.org
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/block/xen-blkback/blkback.c |    6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff mbox series

Patch

--- a/drivers/block/xen-blkback/blkback.c
+++ b/drivers/block/xen-blkback/blkback.c
@@ -860,10 +860,8 @@  again:
 			break;
 	}
 
-	if (segs_to_map) {
+	if (segs_to_map)
 		ret = gnttab_map_refs(map, NULL, pages_to_gnt, segs_to_map);
-		BUG_ON(ret);
-	}
 
 	/*
 	 * Now swizzle the MFN in our domain with the MFN from the other domain
@@ -878,7 +876,7 @@  again:
 				pr_debug("invalid buffer -- could not remap it\n");
 				put_free_pages(ring, &pages[seg_idx]->page, 1);
 				pages[seg_idx]->handle = BLKBACK_INVALID_HANDLE;
-				ret |= 1;
+				ret |= !ret;
 				goto next;
 			}
 			pages[seg_idx]->handle = map[new_map_idx].handle;