| Message ID | 20210730134155.1005358-1-chouhan.shreyansh630@gmail.com (mailing list archive) |
|---|---|
| State | Changes Requested |
| Delegated to: | Herbert Xu |
| Headers | show |
| Series | crypto: add missing kernel_fpu_end() call | expand |
On Fri, Jul 30, 2021 at 07:11:55PM +0530, Shreyansh Chouhan wrote: > xts_crypt() code doesn't call kernel_fpu_end() after calling > kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end() > for this case. > > Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com > Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com> > --- > arch/x86/crypto/aesni-intel_glue.c | 3 +++ > 1 file changed, 3 insertions(+) Ard? > diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c > index 2144e54a6c89..bd55a0cd7bde 100644 > --- a/arch/x86/crypto/aesni-intel_glue.c > +++ b/arch/x86/crypto/aesni-intel_glue.c > @@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) > kernel_fpu_begin(); > } > > + if (walk.nbytes == 0) > + kernel_fpu_end(); > + > if (unlikely(tail > 0 && !err)) { > struct scatterlist sg_src[2], sg_dst[2]; > struct scatterlist *src, *dst; > -- > 2.31.1
On Fri, 6 Aug 2021 at 10:23, Herbert Xu <herbert@gondor.apana.org.au> wrote: > > On Fri, Jul 30, 2021 at 07:11:55PM +0530, Shreyansh Chouhan wrote: > > xts_crypt() code doesn't call kernel_fpu_end() after calling > > kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end() > > for this case. > > > > Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com > > Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com> > > --- > > arch/x86/crypto/aesni-intel_glue.c | 3 +++ > > 1 file changed, 3 insertions(+) > > Ard? > > > diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c > > index 2144e54a6c89..bd55a0cd7bde 100644 > > --- a/arch/x86/crypto/aesni-intel_glue.c > > +++ b/arch/x86/crypto/aesni-intel_glue.c > > @@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) > > kernel_fpu_begin(); > > } > > > > + if (walk.nbytes == 0) > > + kernel_fpu_end(); > > + Don't we end up calling kernel_fpu_end() twice this way if we do enter the while() loop at least once? > > if (unlikely(tail > 0 && !err)) { > > struct scatterlist sg_src[2], sg_dst[2]; > > struct scatterlist *src, *dst; > > -- > > 2.31.1 > > -- > Email: Herbert Xu <herbert@gondor.apana.org.au> > Home Page: http://gondor.apana.org.au/~herbert/ > PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt
On Fri, 6 Aug 2021 at 11:05, Ard Biesheuvel <ardb@kernel.org> wrote: > > On Fri, 6 Aug 2021 at 10:23, Herbert Xu <herbert@gondor.apana.org.au> wrote: > > > > On Fri, Jul 30, 2021 at 07:11:55PM +0530, Shreyansh Chouhan wrote: > > > xts_crypt() code doesn't call kernel_fpu_end() after calling > > > kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end() > > > for this case. > > > > > > Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com > > > Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com> > > > --- > > > arch/x86/crypto/aesni-intel_glue.c | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > Ard? > > > > > diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c > > > index 2144e54a6c89..bd55a0cd7bde 100644 > > > --- a/arch/x86/crypto/aesni-intel_glue.c > > > +++ b/arch/x86/crypto/aesni-intel_glue.c > > > @@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) > > > kernel_fpu_begin(); > > > } > > > > > > + if (walk.nbytes == 0) > > > + kernel_fpu_end(); > > > + > > Don't we end up calling kernel_fpu_end() twice this way if we do enter > the while() loop at least once? > How about the below instead, does that work? --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -849,7 +849,7 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) return -EINVAL; err = skcipher_walk_virt(&walk, req, false); - if (err) + if (err || !walk.nbytes) return err; if (unlikely(tail > 0 && walk.nbytes < walk.total)) {
Hi, On Fri, Aug 06, 2021 at 11:07:43AM +0200, Ard Biesheuvel wrote: > On Fri, 6 Aug 2021 at 11:05, Ard Biesheuvel <ardb@kernel.org> wrote: > > > > On Fri, 6 Aug 2021 at 10:23, Herbert Xu <herbert@gondor.apana.org.au> wrote: > > > > > > On Fri, Jul 30, 2021 at 07:11:55PM +0530, Shreyansh Chouhan wrote: > > > > xts_crypt() code doesn't call kernel_fpu_end() after calling > > > > kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end() > > > > for this case. > > > > > > > > Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com > > > > Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com> > > > > --- > > > > arch/x86/crypto/aesni-intel_glue.c | 3 +++ > > > > 1 file changed, 3 insertions(+) > > > > > > Ard? > > > > > > > diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c > > > > index 2144e54a6c89..bd55a0cd7bde 100644 > > > > --- a/arch/x86/crypto/aesni-intel_glue.c > > > > +++ b/arch/x86/crypto/aesni-intel_glue.c > > > > @@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) > > > > kernel_fpu_begin(); > > > > } > > > > > > > > + if (walk.nbytes == 0) > > > > + kernel_fpu_end(); > > > > + > > > > Don't we end up calling kernel_fpu_end() twice this way if we do enter > > the while() loop at least once? > > Oh ha, we do. I missed that. > > How about the below instead, does that work? > This should work. I will resend the updated patch. > --- a/arch/x86/crypto/aesni-intel_glue.c > +++ b/arch/x86/crypto/aesni-intel_glue.c > @@ -849,7 +849,7 @@ static int xts_crypt(struct skcipher_request *req, > bool encrypt) > return -EINVAL; > > err = skcipher_walk_virt(&walk, req, false); > - if (err) > + if (err || !walk.nbytes) > return err; > > if (unlikely(tail > 0 && walk.nbytes < walk.total)) { Thanks a lot for the review. Regards, Shreyansh Chouhan
diff --git a/arch/x86/crypto/aesni-intel_glue.c b/arch/x86/crypto/aesni-intel_glue.c index 2144e54a6c89..bd55a0cd7bde 100644 --- a/arch/x86/crypto/aesni-intel_glue.c +++ b/arch/x86/crypto/aesni-intel_glue.c @@ -894,6 +894,9 @@ static int xts_crypt(struct skcipher_request *req, bool encrypt) kernel_fpu_begin(); } + if (walk.nbytes == 0) + kernel_fpu_end(); + if (unlikely(tail > 0 && !err)) { struct scatterlist sg_src[2], sg_dst[2]; struct scatterlist *src, *dst;
xts_crypt() code doesn't call kernel_fpu_end() after calling kernel_fpu_begin() if walk.nbytes is 0. Add a call to kernel_fpu_end() for this case. Reported-by: syzbot+20191dc583eff8602d2d@syzkaller.appspotmail.com Signed-off-by: Shreyansh Chouhan <chouhan.shreyansh630@gmail.com> --- arch/x86/crypto/aesni-intel_glue.c | 3 +++ 1 file changed, 3 insertions(+)