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authorMark O'Donovan <shiftee@posteo.net>2023-08-04 09:32:18 +0000
committerHerbert Xu <herbert@gondor.apana.org.au>2023-08-11 19:19:52 +0800
commit9e47a758b70167c9301d2b44d2569f86c7796f2d (patch)
treef8c04f99ee1676efb3a0827c4fa5e7933598f145 /lib/crypto
parent2a598d0b2800aa23ba51adcf060cec524aaa63b2 (diff)
crypto: lib/mpi - avoid null pointer deref in mpi_cmp_ui()
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> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'lib/crypto')
-rw-r--r--lib/crypto/mpi/mpi-cmp.c8
1 files changed, 6 insertions, 2 deletions
diff --git a/lib/crypto/mpi/mpi-cmp.c b/lib/crypto/mpi/mpi-cmp.c
index c4cfa3ff0581..0835b6213235 100644
--- a/lib/crypto/mpi/mpi-cmp.c
+++ b/lib/crypto/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)