In the Linux kernel, the following vulnerability has been resolved:
wifi: wilc1000: fix dma_buffer leak on bus acquire failure
wilc_wlan_firmware_download() allocates dma_buffer with kmalloc() at
the top of the function and uses a ‘fail:’ label to free it via
kfree(dma_buffer) on error.
All later error paths correctly use ‘goto fail’ to route through this
cleanup. However, the early failure path after the first acquire_bus()
call uses a bare ‘return ret;’, which leaks dma_buffer whenever the bus
acquire fails.
Replace the early return with goto fail so the existing cleanup path
runs.
Found via a custom Coccinelle semantic patch hunting for kmalloc’d
locals leaked on early-return error paths in driver firmware-download
code.
