In the Linux kernel, the following vulnerability has been resolved:
mtd: block2mtd: Fix divide error when erase_size is zero
The erase size is parsed from the “block2mtd” module parameter and can
be set to zero. add_device() then evaluates
if (size % erase_size)
with a zero divisor, which triggers a divide error:
divide error: 0000 [#1] PREEMPT SMP PTI
RIP: 0010:add_device drivers/mtd/devices/block2mtd.c:296 [inline]
RIP: 0010:block2mtd_setup2+0x592/0xda0 drivers/mtd/devices/block2mtd.c:459
Call Trace:
block2mtd_setup+0x27/0xe0 drivers/mtd/devices/block2mtd.c:476
param_attr_store+0x214/0x310 kernel/params.c:589
module_attr_store+0x65/0x90 kernel/params.c:904
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
…
Reject a zero erase size before performing the modulo operation so the
existing “erasesize must be a divisor of device size” error path
reports the invalid argument and frees the device.
