diff options
| author | Herbert Xu <herbert@gondor.apana.org.au> | 2019-06-24 18:32:26 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-07-10 09:54:40 +0200 |
| commit | 9fbe87fc25ad9b169505ab6ad282c7072b2d275e (patch) | |
| tree | 2d44dcca46f5187caa512ea3c364bca0fa4a75dd /lib | |
| parent | 76cdeea3b1fdfbcbfbcf5c9c15d48639323be4e8 (diff) | |
| download | linux-stable-9fbe87fc25ad9b169505ab6ad282c7072b2d275e.tar.gz linux-stable-9fbe87fc25ad9b169505ab6ad282c7072b2d275e.tar.bz2 linux-stable-9fbe87fc25ad9b169505ab6ad282c7072b2d275e.zip | |
lib/mpi: Fix karactx leak in mpi_powm
commit c8ea9fce2baf7b643384f36f29e4194fa40d33a6 upstream.
Sometimes mpi_powm will leak karactx because a memory allocation
failure causes a bail-out that skips the freeing of karactx. This
patch moves the freeing of karactx to the end of the function like
everything else so that it can't be skipped.
Reported-by: syzbot+f7baccc38dcc1e094e77@syzkaller.appspotmail.com
Fixes: cdec9cb5167a ("crypto: GnuPG based MPI lib - source files...")
Cc: <stable@vger.kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'lib')
| -rw-r--r-- | lib/mpi/mpi-pow.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/lib/mpi/mpi-pow.c b/lib/mpi/mpi-pow.c index 468fb7cd1221..edf345b7f06b 100644 --- a/lib/mpi/mpi-pow.c +++ b/lib/mpi/mpi-pow.c @@ -37,6 +37,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) { mpi_ptr_t mp_marker = NULL, bp_marker = NULL, ep_marker = NULL; + struct karatsuba_ctx karactx = {}; mpi_ptr_t xp_marker = NULL; mpi_ptr_t tspace = NULL; mpi_ptr_t rp, ep, mp, bp; @@ -164,13 +165,11 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) int c; mpi_limb_t e; mpi_limb_t carry_limb; - struct karatsuba_ctx karactx; xp = xp_marker = mpi_alloc_limb_space(2 * (msize + 1)); if (!xp) goto enomem; - memset(&karactx, 0, sizeof karactx); negative_result = (ep[0] & 1) && base->sign; i = esize - 1; @@ -295,8 +294,6 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) if (mod_shift_cnt) mpihelp_rshift(rp, rp, rsize, mod_shift_cnt); MPN_NORMALIZE(rp, rsize); - - mpihelp_release_karatsuba_ctx(&karactx); } if (negative_result && rsize) { @@ -313,6 +310,7 @@ int mpi_powm(MPI res, MPI base, MPI exp, MPI mod) leave: rc = 0; enomem: + mpihelp_release_karatsuba_ctx(&karactx); if (assign_rp) mpi_assign_limb_space(res, rp, size); if (mp_marker) |