From: Salah Triki <salah.triki@gmail.com> stable inclusion from stable-v5.10.252 commit 2b2ad7ad4a28ffdb9f94e6d979b88a5b12b71681 category: bugfix bugzilla: 189268 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7 ] `css_alloc_subchannel()` calls `device_initialize()` before setting up the DMA masks. If `dma_set_coherent_mask()` or `dma_set_mask()` fails, the error path frees the subchannel structure directly, bypassing the device model reference counting. Once `device_initialize()` has been called, the embedded struct device must be released via `put_device()`, allowing the release callback to free the container structure. Fix the error path by dropping the initial device reference with `put_device()` instead of calling `kfree()` directly. This ensures correct device lifetime handling and avoids potential use-after-free or double-free issues. Fixes: e5dcf0025d7af ("s390/css: move subchannel lock allocation") Signed-off-by: Salah Triki <salah.triki@gmail.com> Reviewed-by: Vineeth Vijayan <vneethv@linux.ibm.com> Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Lin Yujun <linyujun809@h-partners.com> --- drivers/s390/cio/css.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/s390/cio/css.c b/drivers/s390/cio/css.c index cf2c3c4c590f..e5e20ea850aa 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -241,7 +241,7 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid, return sch; err: - kfree(sch); + put_device(&sch->dev); return ERR_PTR(ret); } -- 2.22.0