On Mon, Sep 13, 2021 at 09:52:33PM +0530, Naresh Kamboju wrote: > On Mon, 13 Sept 2021 at 19:51, Greg Kroah-Hartman > <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > > > > From: Baokun Li <libaokun1@xxxxxxxxxx> > > > > [ Upstream commit fad7cd3310db3099f95dd34312c77740fbc455e5 ] > > > > 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@xxxxxxxxxx> > > Signed-off-by: Baokun Li <libaokun1@xxxxxxxxxx> > > Reviewed-by: Josef Bacik <josef@xxxxxxxxxxxxxx> > > Link: https://lore.kernel.org/r/20210804021212.990223-1-libaokun1@xxxxxxxxxx > > [axboe: dropped unlikely()] > > Signed-off-by: Jens Axboe <axboe@xxxxxxxxx> > > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > > --- > > drivers/block/nbd.c | 6 ++++-- > > 1 file changed, 4 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c > > index 19f5d5a8b16a..acf3f85bf3c7 100644 > > --- a/drivers/block/nbd.c > > +++ b/drivers/block/nbd.c > > @@ -1388,6 +1388,7 @@ 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: > > @@ -1402,8 +1403,9 @@ 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 (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; > > arm clang-10, clang-11, clang-12 and clang-13 builds failed. > due to this commit on 5.14 and 5.13 on following configs, > - footbridge_defconfig > - mini2440_defconfig > - s3c2410_defconfig > > This was already reported on the mailing list. > > ERROR: modpost: "__mulodi4" [drivers/block/nbd.ko] undefined! #1438 > https://github.com/ClangBuiltLinux/linux/issues/1438 > > [PATCH 00/10] raise minimum GCC version to 5.1 > https://lore.kernel.org/lkml/20210910234047.1019925-1-ndesaulniers@xxxxxxxxxx/ > > linux-next: build failure while building Linus' tree > https://lore.kernel.org/all/20210909182525.372ee687@xxxxxxxxxxxxxxxx/ > > Full build log, > https://gitlab.com/Linaro/lkft/mirrors/stable/linux-stable-rc/-/jobs/1585407346#L1111 Has anyone submitted a fix for this upstream yet? I can't seem to find one :(
