From: Junrui Luo Date: Thu, 16 Apr 2026 03:39:56 +0000 (+0800) Subject: md/raid10: fix divide-by-zero in setup_geo() with zero far_copies X-Git-Tag: v7.1-rc2~13^2^2~8 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=9aa6d860b0930e2f72795665c42c44252a558a0c;p=thirdparty%2Fkernel%2Flinux.git md/raid10: fix divide-by-zero in setup_geo() with zero far_copies setup_geo() extracts near_copies (nc) and far_copies (fc) from the user-provided layout parameter without checking for zero. When fc=0 with the "improved" far set layout selected, 'geo->far_set_size = disks / fc' triggers a divide-by-zero. Validate nc and fc immediately after extraction, returning -1 if either is zero. Fixes: 475901aff158 ("MD RAID10: Improve redundancy for 'far' and 'offset' algorithms (part 1)") Cc: stable@vger.kernel.org Signed-off-by: Junrui Luo Link: https://lore.kernel.org/linux-raid/SYBPR01MB7881A5E2556806CC1D318582AF232@SYBPR01MB7881.ausprd01.prod.outlook.com Signed-off-by: Yu Kuai --- diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 4901ebe45c87..39085e7dd6d2 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -3791,6 +3791,8 @@ static int setup_geo(struct geom *geo, struct mddev *mddev, enum geo_type new) nc = layout & 255; fc = (layout >> 8) & 255; fo = layout & (1<<16); + if (!nc || !fc) + return -1; geo->raid_disks = disks; geo->near_copies = nc; geo->far_copies = fc;