FAILED: patch "[PATCH] dm-verity-fec: fix the size of dm_verity_fec_io::erasures" failed to apply to 5.15-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.15-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y
git checkout FETCH_HEAD
git cherry-pick -x a7fca324d7d90f7b139d4d32747c83a629fdb446
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051214-undying-maybe-3c0e@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From a7fca324d7d90f7b139d4d32747c83a629fdb446 Mon Sep 17 00:00:00 2001
From: Eric Biggers <ebiggers@kernel.org>
Date: Thu, 5 Feb 2026 20:59:23 -0800
Subject: [PATCH] dm-verity-fec: fix the size of dm_verity_fec_io::erasures

At most 25 entries in dm_verity_fec_io::erasures are used: the maximum
number of FEC roots plus one.  Therefore, set the array size
accordingly.  This reduces the size of dm_verity_fec_io by 912 bytes.

Note: a later commit introduces a constant DM_VERITY_FEC_MAX_ROOTS,
which allows the size to be more clearly expressed as
DM_VERITY_FEC_MAX_ROOTS + 1.  This commit just fixes the size first.

Fixes: a739ff3f543a ("dm verity: add support for forward error correction")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

diff --git a/drivers/md/dm-verity-fec.h b/drivers/md/dm-verity-fec.h
index 35d28d9f8a9b..32ca2bfee1db 100644
--- a/drivers/md/dm-verity-fec.h
+++ b/drivers/md/dm-verity-fec.h
@@ -47,7 +47,8 @@ struct dm_verity_fec {
 /* per-bio data */
 struct dm_verity_fec_io {
 	struct rs_control *rs;	/* Reed-Solomon state */
-	int erasures[DM_VERITY_FEC_MAX_RSN];	/* erasures for decode_rs8 */
+	/* erasures for decode_rs8 */
+	int erasures[DM_VERITY_FEC_RSM - DM_VERITY_FEC_MIN_RSN + 1];
 	u8 *output;		/* buffer for corrected output */
 	unsigned int level;		/* recursion level */
 	unsigned int nbufs;		/* number of buffers allocated */