| Message ID | 20230804093218.418276-1-shiftee@posteo.net |
|---|---|
| State | New |
| Headers | show |
| Series | [RESEND] lib/mpi: avoid null pointer deref in mpi_cmp_ui() | expand |
On Fri, Aug 04, 2023 at 09:32:18AM +0000, Mark O'Donovan wrote: > During NVMeTCP Authentication a controller can trigger a kernel > oops by specifying the 8192 bit Diffie Hellman group and passing > a correctly sized, but zeroed Diffie Hellamn value. > mpi_cmp_ui() was detecting this if the second parameter was 0, > but 1 is passed from dh_is_pubkey_valid(). This causes the null > pointer u->d to be dereferenced towards the end of mpi_cmp_ui() > > Signed-off-by: Mark O'Donovan <shiftee@posteo.net> > --- > lib/mpi/mpi-cmp.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) Patch applied. Thanks.
diff --git a/lib/mpi/mpi-cmp.c b/lib/mpi/mpi-cmp.c index c4cfa3ff0581..0835b6213235 100644 --- a/lib/mpi/mpi-cmp.c +++ b/lib/mpi/mpi-cmp.c @@ -25,8 +25,12 @@ int mpi_cmp_ui(MPI u, unsigned long v) mpi_limb_t limb = v; mpi_normalize(u); - if (!u->nlimbs && !limb) - return 0; + if (u->nlimbs == 0) { + if (v == 0) + return 0; + else + return -1; + } if (u->sign) return -1; if (u->nlimbs > 1)
During NVMeTCP Authentication a controller can trigger a kernel oops by specifying the 8192 bit Diffie Hellman group and passing a correctly sized, but zeroed Diffie Hellamn value. mpi_cmp_ui() was detecting this if the second parameter was 0, but 1 is passed from dh_is_pubkey_valid(). This causes the null pointer u->d to be dereferenced towards the end of mpi_cmp_ui() Signed-off-by: Mark O'Donovan <shiftee@posteo.net> --- lib/mpi/mpi-cmp.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)