5.4-stable review patch. If anyone has any objections, please let me know.
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From: Ioana Ciornei ioana.ciornei@nxp.com
[ 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 ioana.ciornei@nxp.com Link: https://lore.kernel.org/r/20250408105814.2837951-2-ioana.ciornei@nxp.com Signed-off-by: Christophe Leroy christophe.leroy@csgroup.eu Signed-off-by: Sasha Levin sashal@kernel.org --- 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 5c9bf2e065520..3a2107d1c5394 100644 --- a/drivers/bus/fsl-mc/fsl-mc-bus.c +++ b/drivers/bus/fsl-mc/fsl-mc-bus.c @@ -679,8 +679,10 @@ 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; }