| Message ID | 20210804021212.990223-1-libaokun1@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [-next,v3] nbd: add the check to prevent overflow in __nbd_ioctl() | expand |
在 2021/8/4 10:12, Baokun Li 写道: > If user specify a large enough value of NBD blocks option, it may trigger > signed integer overflow which may lead to nbd->config->bytesize becomes a > large or small value, zero in particular. > > UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31 > signed integer overflow: > 1024 * 4611686155866341414 cannot be represented in type 'long long int' > [...] > Call trace: > [...] > handle_overflow+0x188/0x1dc lib/ubsan.c:192 > __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 > nbd_size_set drivers/block/nbd.c:325 [inline] > __nbd_ioctl drivers/block/nbd.c:1342 [inline] > nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395 > __blkdev_driver_ioctl block/ioctl.c:311 [inline] > [...] > > Although it is not a big deal, still silence the UBSAN by limit > the input value. > > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Baokun Li <libaokun1@huawei.com> > --- > V1->V2: > Use check_mul_overflow(). > V2->V3: > The check_mul_overflow function requires the same input parameter type. > > drivers/block/nbd.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index c38317979f74..5a42b838d26c 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -1384,6 +1384,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, > unsigned int cmd, unsigned long arg) > { > struct nbd_config *config = nbd->config; > + loff_t bytesize; > > switch (cmd) { > case NBD_DISCONNECT: > @@ -1398,8 +1399,11 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, > case NBD_SET_SIZE: > return nbd_set_size(nbd, arg, config->blksize); > case NBD_SET_SIZE_BLOCKS: > - return nbd_set_size(nbd, arg * config->blksize, > - config->blksize); > + if (unlikely(check_mul_overflow((loff_t)arg, > + config->blksize, > + &bytesize))) > + return -EINVAL; > + return nbd_set_size(nbd, bytesize, config->blksize); > case NBD_SET_TIMEOUT: > nbd_set_cmd_timeout(nbd, arg); > return 0; ping
On 8/3/21 10:12 PM, Baokun Li wrote: > If user specify a large enough value of NBD blocks option, it may trigger > signed integer overflow which may lead to nbd->config->bytesize becomes a > large or small value, zero in particular. > > UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31 > signed integer overflow: > 1024 * 4611686155866341414 cannot be represented in type 'long long int' > [...] > Call trace: > [...] > handle_overflow+0x188/0x1dc lib/ubsan.c:192 > __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 > nbd_size_set drivers/block/nbd.c:325 [inline] > __nbd_ioctl drivers/block/nbd.c:1342 [inline] > nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395 > __blkdev_driver_ioctl block/ioctl.c:311 [inline] > [...] > > Although it is not a big deal, still silence the UBSAN by limit > the input value. > > Reported-by: Hulk Robot <hulkci@huawei.com> > Signed-off-by: Baokun Li <libaokun1@huawei.com> > --- > V1->V2: > Use check_mul_overflow(). > V2->V3: > The check_mul_overflow function requires the same input parameter type. > > drivers/block/nbd.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > index c38317979f74..5a42b838d26c 100644 > --- a/drivers/block/nbd.c > +++ b/drivers/block/nbd.c > @@ -1384,6 +1384,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, > unsigned int cmd, unsigned long arg) > { > struct nbd_config *config = nbd->config; > + loff_t bytesize; > > switch (cmd) { > case NBD_DISCONNECT: > @@ -1398,8 +1399,11 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, > case NBD_SET_SIZE: > return nbd_set_size(nbd, arg, config->blksize); > case NBD_SET_SIZE_BLOCKS: > - return nbd_set_size(nbd, arg * config->blksize, > - config->blksize); > + if (unlikely(check_mul_overflow((loff_t)arg, > + config->blksize, > + &bytesize))) > + return -EINVAL; > + return nbd_set_size(nbd, bytesize, config->blksize); The unlikely isn't needed here, just makes it harder to read the thing, drop it and then you can add Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
On 8/3/21 8:12 PM, Baokun Li wrote: > If user specify a large enough value of NBD blocks option, it may trigger > signed integer overflow which may lead to nbd->config->bytesize becomes a > large or small value, zero in particular. > > UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31 > signed integer overflow: > 1024 * 4611686155866341414 cannot be represented in type 'long long int' > [...] > Call trace: > [...] > handle_overflow+0x188/0x1dc lib/ubsan.c:192 > __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 > nbd_size_set drivers/block/nbd.c:325 [inline] > __nbd_ioctl drivers/block/nbd.c:1342 [inline] > nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395 > __blkdev_driver_ioctl block/ioctl.c:311 [inline] > [...] > > Although it is not a big deal, still silence the UBSAN by limit > the input value. Applied with unlikely() removed.
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c index c38317979f74..5a42b838d26c 100644 --- a/drivers/block/nbd.c +++ b/drivers/block/nbd.c @@ -1384,6 +1384,7 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, unsigned int cmd, unsigned long arg) { struct nbd_config *config = nbd->config; + loff_t bytesize; switch (cmd) { case NBD_DISCONNECT: @@ -1398,8 +1399,11 @@ static int __nbd_ioctl(struct block_device *bdev, struct nbd_device *nbd, case NBD_SET_SIZE: return nbd_set_size(nbd, arg, config->blksize); case NBD_SET_SIZE_BLOCKS: - return nbd_set_size(nbd, arg * config->blksize, - config->blksize); + if (unlikely(check_mul_overflow((loff_t)arg, + config->blksize, + &bytesize))) + return -EINVAL; + return nbd_set_size(nbd, bytesize, config->blksize); case NBD_SET_TIMEOUT: nbd_set_cmd_timeout(nbd, arg); return 0;
If user specify a large enough value of NBD blocks option, it may trigger signed integer overflow which may lead to nbd->config->bytesize becomes a large or small value, zero in particular. UBSAN: Undefined behaviour in drivers/block/nbd.c:325:31 signed integer overflow: 1024 * 4611686155866341414 cannot be represented in type 'long long int' [...] Call trace: [...] handle_overflow+0x188/0x1dc lib/ubsan.c:192 __ubsan_handle_mul_overflow+0x34/0x44 lib/ubsan.c:213 nbd_size_set drivers/block/nbd.c:325 [inline] __nbd_ioctl drivers/block/nbd.c:1342 [inline] nbd_ioctl+0x998/0xa10 drivers/block/nbd.c:1395 __blkdev_driver_ioctl block/ioctl.c:311 [inline] [...] Although it is not a big deal, still silence the UBSAN by limit the input value. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: Baokun Li <libaokun1@huawei.com> --- V1->V2: Use check_mul_overflow(). V2->V3: The check_mul_overflow function requires the same input parameter type. drivers/block/nbd.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)