From f65c75b0b9b5a390bc3beadcde0a6fbc3ad118f7 Mon Sep 17 00:00:00 2001 From: Salah Triki Date: Fri, 30 Jan 2026 21:47:59 +0100 Subject: [PATCH] s390/cio: Fix device lifecycle handling in css_alloc_subchannel() `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 Reviewed-by: Vineeth Vijayan Signed-off-by: Heiko Carstens --- 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 4c85df7a548ef..ac24e019020e8 100644 --- a/drivers/s390/cio/css.c +++ b/drivers/s390/cio/css.c @@ -235,7 +235,7 @@ struct subchannel *css_alloc_subchannel(struct subchannel_id schid, return sch; err: - kfree(sch); + put_device(&sch->dev); return ERR_PTR(ret); } -- 2.47.3