On Thu, 18 Sep 2025 21:08:38 +0800, Guangshuo Li wrote:
kcalloc_node() may fail. When the interrupter array allocation returns NULL, subsequent code uses xhci->interrupters (e.g. in xhci_add_interrupter() and in cleanup paths), leading to a potential NULL pointer dereference.
Check the allocation and bail out to the existing fail path to avoid the NULL dereference.
Fixes: c99b38c412343 ("xhci: add support to allocate several interrupters") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li lgs201920130244@gmail.com
drivers/usb/host/xhci-mem.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/usb/host/xhci-mem.c b/drivers/usb/host/xhci-mem.c index d698095fc88d..da257856e864 100644 --- a/drivers/usb/host/xhci-mem.c +++ b/drivers/usb/host/xhci-mem.c @@ -2505,7 +2505,8 @@ int xhci_mem_init(struct xhci_hcd *xhci, gfp_t flags) "Allocating primary event ring"); xhci->interrupters = kcalloc_node(xhci->max_interrupters, sizeof(*xhci->interrupters), flags, dev_to_node(dev));
- if (!xhci->interrupters)
goto fail;-- 2.43.0
Hi Greg and Mathias,
I noticed that this bug still exists in current 6.6 and 6.12 releases, what would be the sensible course of action to fix it?
The patch from Guangshuo Li is a specific fix and it applies cleanly on those branches. By simulating allocation failure, I confirmed the bug and the fix on 6.6.113, which is identical to the current 6.6.116.
Mainline added an identical check in 83d98dea48eb ("usb: xhci: add individual allocation checks in xhci_mem_init()") which is a cleanup that has a merge conflict at least with 6.6.
The conflict seems superficial and probably the cleanup would have no side effects on 6.6/6.12, but I haven't really reviewed this and maybe it would be simpler to just take the targeted fix?
Regards, Michal