From 21c8815d6685c649809fb1ee7108db061d4efaf0 Mon Sep 17 00:00:00 2001 From: Ioana Ciornei Date: Tue, 8 Apr 2025 13:58:09 +0300 Subject: [PATCH] bus: fsl-mc: fix double-free on mc_dev stable inclusion from stable-v6.6.94 commit 4b23c46eb2d88924b93aca647bde9a4b9cf62cf9 category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICLGFU CVE: CVE-2025-38313 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=4b23c46eb2d88924b93aca647bde9a4b9cf62cf9 -------------------------------- [ Upstream commit d694bf8a9acdbd061596f3e7549bc8cb70750a60 ] The blamed commit tried to simplify how the deallocations are done but, in the process, introduced a double-free on the mc_dev variable. In case the MC device is a DPRC, a new mc_bus is allocated and the mc_dev variable is just a reference to one of its fields. In this circumstance, on the error path only the mc_bus should be freed. This commit introduces back the following checkpatch warning which is a false-positive. WARNING: kfree(NULL) is safe and this check is probably not required + if (mc_bus) + kfree(mc_bus); Fixes: a042fbed0290 ("staging: fsl-mc: simplify couple of deallocations") Signed-off-by: Ioana Ciornei Link: https://lore.kernel.org/r/20250408105814.2837951-2-ioana.ciornei@nxp.com Signed-off-by: Christophe Leroy Signed-off-by: Sasha Levin Signed-off-by: xiaochn --- drivers/bus/fsl-mc/fsl-mc-bus.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/bus/fsl-mc/fsl-mc-bus.c b/drivers/bus/fsl-mc/fsl-mc-bus.c index 2f6d5002e43d5..b405ee330af1f 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -905,8 +905,10 @@ int fsl_mc_device_add(struct fsl_mc_obj_desc *obj_desc, error_cleanup_dev: kfree(mc_dev->regions); - kfree(mc_bus); - kfree(mc_dev); + if (mc_bus) + kfree(mc_bus); + else + kfree(mc_dev); return error; } -- Gitee