linux-kernel - [PATCH v6 2/6] block: sanitize chunk

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20250711080929.3091196-3-john.g.garry@oracle.com>
Date: Fri, 11 Jul 2025 08:09:25 +0000
From: John Garry <john.g.garry@...cle.com>
To: agk@...hat.com, snitzer@...nel.org, mpatocka@...hat.com, song@...nel.org,
        yukuai3@...wei.com, hch@....de, nilay@...ux.ibm.com, axboe@...nel.dk,
        cem@...nel.org
Cc: dm-devel@...ts.linux.dev, linux-kernel@...r.kernel.org,
        linux-raid@...r.kernel.org, linux-block@...r.kernel.org,
        ojaswin@...ux.ibm.com, martin.petersen@...cle.com,
        akpm@...ux-foundation.org, linux-xfs@...r.kernel.org,
        djwong@...nel.org, John Garry <john.g.garry@...cle.com>
Subject: [PATCH v6 2/6] block: sanitize chunk_sectors for atomic write limits

Currently we just ensure that a non-zero value in chunk_sectors aligns
with any atomic write boundary, as the blk boundary functionality uses
both these values.

However it is also improper to have atomic write unit max > chunk_sectors
(for non-zero chunk_sectors), as this would lead to splitting of atomic
write bios (which is disallowed).

Sanitize atomic write unit max against chunk_sectors to avoid any
potential problems.

Fixes: d00eea91deaf3 ("block: Add extra checks in blk_validate_atomic_write_limits()")
Reviewed-by: Nilay Shroff <nilay@...ux.ibm.com>
Signed-off-by: John Garry <john.g.garry@...cle.com>
---
 block/blk-settings.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/block/blk-settings.c b/block/blk-settings.c
index a000daafbfb48..a2c089167174e 100644
--- a/block/blk-settings.c
+++ b/block/blk-settings.c
@@ -180,6 +180,7 @@ static void blk_atomic_writes_update_limits(struct queue_limits *lim)
 
 static void blk_validate_atomic_write_limits(struct queue_limits *lim)
 {
+	unsigned long long chunk_bytes = lim->chunk_sectors << SECTOR_SHIFT;
 	unsigned int boundary_sectors;
 
 	if (!(lim->features & BLK_FEAT_ATOMIC_WRITES))
@@ -202,6 +203,10 @@ static void blk_validate_atomic_write_limits(struct queue_limits *lim)
 			 lim->atomic_write_hw_max))
 		goto unsupported;
 
+	if (WARN_ON_ONCE(chunk_bytes &&
+			lim->atomic_write_hw_unit_max > chunk_bytes))
+		goto unsupported;
+
 	boundary_sectors = lim->atomic_write_hw_boundary >> SECTOR_SHIFT;
 
 	if (boundary_sectors) {
-- 
2.43.5