From e887544d7620f1d3cef017e45df7bc625182caff Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Fri, 15 Sep 2023 13:03:28 -0700 Subject: md/md-linear: Annotate struct linear_conf with __counted_by Prepare for the coming implementation by GCC and Clang of the __counted_by attribute. Flexible array members annotated with __counted_by can have their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS (for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family functions). As found with Coccinelle[1], add __counted_by for struct linear_conf. Additionally, since the element count member must be set before accessing the annotated flexible array member, move its initialization earlier. [1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci Cc: Song Liu Cc: linux-raid@vger.kernel.org Signed-off-by: Kees Cook Reviewed-by: Gustavo A. R. Silva Signed-off-by: Song Liu Link: https://lore.kernel.org/r/20230915200328.never.064-kees@kernel.org --- drivers/md/md-linear.c | 26 +++++++++++++------------- 1 file changed, 13 insertions(+), 13 deletions(-) (limited to 'drivers/md/md-linear.c') diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c index 71ac99646827..ae2826e9645b 100644 --- a/drivers/md/md-linear.c +++ b/drivers/md/md-linear.c @@ -69,6 +69,19 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks) if (!conf) return NULL; + /* + * conf->raid_disks is copy of mddev->raid_disks. The reason to + * keep a copy of mddev->raid_disks in struct linear_conf is, + * mddev->raid_disks may not be consistent with pointers number of + * conf->disks[] when it is updated in linear_add() and used to + * iterate old conf->disks[] earray in linear_congested(). + * Here conf->raid_disks is always consitent with number of + * pointers in conf->disks[] array, and mddev->private is updated + * with rcu_assign_pointer() in linear_addr(), such race can be + * avoided. + */ + conf->raid_disks = raid_disks; + cnt = 0; conf->array_sectors = 0; @@ -112,19 +125,6 @@ static struct linear_conf *linear_conf(struct mddev *mddev, int raid_disks) conf->disks[i-1].end_sector + conf->disks[i].rdev->sectors; - /* - * conf->raid_disks is copy of mddev->raid_disks. The reason to - * keep a copy of mddev->raid_disks in struct linear_conf is, - * mddev->raid_disks may not be consistent with pointers number of - * conf->disks[] when it is updated in linear_add() and used to - * iterate old conf->disks[] earray in linear_congested(). - * Here conf->raid_disks is always consitent with number of - * pointers in conf->disks[] array, and mddev->private is updated - * with rcu_assign_pointer() in linear_addr(), such race can be - * avoided. - */ - conf->raid_disks = raid_disks; - return conf; out: -- cgit v1.2.3