mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-02-13 18:56:25 -05:00
c33efdfcfa
Commit8f1fc1bf1a("dma: contiguous: Reserve default CMA heap") introduced a bug where dma_heap_cma_register_heap() is called with a NULL pointer when dma_contiguous_reserve_area() fails to reserve the CMA area. When dma_contiguous_reserve_area() fails, dma_contiguous_default_area remains NULL (initialized as a global variable), but the code doesn't check the return value and proceeds to call dma_heap_cma_register_heap() with this NULL pointer. Later during boot, add_cma_heaps() iterates through the dma_areas[] array and attempts to register heaps. When it encounters the NULL pointer stored by the earlier call, it crashes in __add_cma_heap() -> dma_heap_add() when trying to dereference the NULL CMA pointer. The crash manifests as: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000038 ... Call trace: dma_heap_add+0x40/0x2b0 __add_cma_heap+0x80/0xe0 add_cma_heaps+0x64/0xb0 do_one_initcall+0x60/0x318 kernel_init_freeable+0x260/0x2f0 kernel_init+0x2c/0x168 ret_from_fork+0x10/0x20 Fix this by checking the return value of dma_contiguous_reserve_area() and only calling dma_heap_cma_register_heap() when the reservation succeeds. Fixes:8f1fc1bf1a("dma: contiguous: Reserve default CMA heap") Signed-off-by: Shanker Donthineni <sdonthineni@nvidia.com> Reviewed-by: T.J. Mercier <tjmercier@google.com> Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com> Link: https://lore.kernel.org/r/20260129181317.2429196-1-sdonthineni@nvidia.com