John Garry <john.g.garry@xxxxxxxxxx> writes: > On 01/06/2024 21:23, Andreas Hindborg wrote: >> From: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> >> Block size should be between 512 > > >>and 4096 > > Or PAGE_SIZE? Right 👍 > > and be a power of 2. The current >> check does not validate this, so update the check. >> Without this patch, null_blk would Oops due to a null pointer deref when >> loaded with bs=1536 [1]. >> Link: >> https://urldefense.com/v3/__https://lore.kernel.org/all/87wmn8mocd.fsf@xxxxxxxxxxxx/__;!!ACWV5N9M2RV99hQ!OWXI3DGxeIAWvKfM5oVSiA5fTWmiRvUctIdVrcBcKnO_HF-vgkarVfd27jkvQ1-JjNgX5IFIvBWcsUttvg$ >> Signed-off-by: Andreas Hindborg <a.hindborg@xxxxxxxxxxx> >> --- >> drivers/block/null_blk/main.c | 6 ++++-- >> 1 file changed, 4 insertions(+), 2 deletions(-) >> diff --git a/drivers/block/null_blk/main.c b/drivers/block/null_blk/main.c >> index eb023d267369..6a26888c52bb 100644 >> --- a/drivers/block/null_blk/main.c >> +++ b/drivers/block/null_blk/main.c >> @@ -1823,8 +1823,10 @@ static int null_validate_conf(struct nullb_device *dev) >> dev->queue_mode = NULL_Q_MQ; >> } >> - dev->blocksize = round_down(dev->blocksize, 512); >> - dev->blocksize = clamp_t(unsigned int, dev->blocksize, 512, 4096); >> + if ((dev->blocksize < 512 || dev->blocksize > 4096) || >> + ((dev->blocksize & (dev->blocksize - 1)) != 0)) { >> + return -EINVAL; >> + } > > Looks like blk_validate_block_size(), modulo PAGE_SIZE check Cool, I will use that instead. BR Andreas
