From: Denis Arefev <arefev@xxxxxxxxx> commit 97bbf9e312c3fbaf0baa56120238825d2eb23b8a upstream. Added a check for ubi_num for negative numbers If the variable ubi_num takes negative values then we get: qemu-system-arm ... -append "ubi.mtd=0,0,0,-22222345" ... [ 0.745065] ubi_attach_mtd_dev from ubi_init+0x178/0x218 [ 0.745230] ubi_init from do_one_initcall+0x70/0x1ac [ 0.745344] do_one_initcall from kernel_init_freeable+0x198/0x224 [ 0.745474] kernel_init_freeable from kernel_init+0x18/0x134 [ 0.745600] kernel_init from ret_from_fork+0x14/0x28 [ 0.745727] Exception stack(0x90015fb0 to 0x90015ff8) Found by Linux Verification Center (linuxtesting.org) with SVACE. Fixes: 83ff59a06663 ("UBI: support ubi_num on mtd.ubi command line") Cc: stable@xxxxxxxxxxxxxxx Signed-off-by: Denis Arefev <arefev@xxxxxxxxx> Reviewed-by: Zhihao Cheng <chengzhihao1@xxxxxxxxxx> Signed-off-by: Richard Weinberger <richard@xxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/mtd/ubi/build.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/drivers/mtd/ubi/build.c +++ b/drivers/mtd/ubi/build.c @@ -1462,7 +1462,7 @@ static int ubi_mtd_param_parse(const cha if (token) { int err = kstrtoint(token, 10, &p->ubi_num); - if (err) { + if (err || p->ubi_num < UBI_DEV_NUM_AUTO) { pr_err("UBI error: bad value for ubi_num parameter: %s\n", token); return -EINVAL; Patches currently in stable-queue which might be from arefev@xxxxxxxxx are queue-6.6/ubi-add-a-check-for-ubi_num.patch