Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: xfrm: Check for underflow in xfrm_state_mtu Leo Lin reported OOB write issue in esp component: xfrm_state_mtu() returns u32 but performs its arithmetic in unsigned modulo-2^32 space using an attacker-influenced "header_len + authsize + net_adj" subtracted from a small "mtu" argument. A nobody user can install an IPv4 ESP tunnel SA with a large authentication key (XFRMA_ALG_AUTH_TRUNC, e.g. hmac(sha512), 64-byte key, 64-byte trunc), configure a small interface MTU (68 bytes), and set XFRMA_TFCPAD to a large value. When a single UDP datagram is then sent through the tunnel, xfrm_state_mtu() underflows to a near-2^32 value, and esp_output() consumes it as a signed int via: padto = min(x->tfcpad, xfrm_state_mtu(x, mtu_cached)) esp.tfclen = padto - skb->len (assigned to int) esp.tfclen ends up negative (e.g. -207). It is sign-extended to size_t when passed to memset() inside esp_output_fill_trailer(), producing a ~16 EB write of zeroes at skb_tail_pointer(skb). KASAN logs it as "Write of size 18446744073709551537 at addr ffff888...". Check for underflow and return 1. This causes the sendmsg attempt to fail with ENETUNREACH.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected c5c2523893747f88a83376abad310c8ad13f7197 before 8014f70c4e6e5ab101ae3860a614e65e988372e3; affected c5c2523893747f88a83376abad310c8ad13f7197 before 1021d2877b689a648b27815c854557a917122e93; affected c5c2523893747f88a83376abad310c8ad13f7197 before 2a41b1b31c61c52b972278ce1732a1443f5e89ed; affected c5c2523893747f88a83376abad310c8ad13f7197 before fccd685b32df5aaf6bad4381eeda216468e283f0; affected c5c2523893747f88a83376abad310c8ad13f7197 before 820e501be8aee4b365d218d83227b314309c5fda; affected c5c2523893747f88a83376abad310c8ad13f7197 before 82ac903e0b519849647657b8c48d21237ada06a2; affected c5c2523893747f88a83376abad310c8ad13f7197 before 3db50ceeacb52806d8fe86fb1dfe944df0b9f789; affected c5c2523893747f88a83376abad310c8ad13f7197 before 742b04d0550b0ec89dcbc99537ec88653bd1ad90 |
| Linux / Linux | affected 2.6.22; unaffected 0 before 2.6.22; unaffected 5.10.259 through 5.10.*; unaffected 5.15.210 through 5.15.*; unaffected 6.1.176 through 6.1.*; unaffected 6.6.143 through 6.6.*; unaffected 6.12.93 through 6.12.*; unaffected 6.18.35 through 6.18.*; unaffected 7.0.12 through 7.0.*; unaffected 7.1 through * |
CWE
No CWE identifiers supplied.
References
- https://git.kernel.org/stable/c/8014f70c4e6e5ab101ae3860a614e65e988372e3
- https://git.kernel.org/stable/c/1021d2877b689a648b27815c854557a917122e93
- https://git.kernel.org/stable/c/2a41b1b31c61c52b972278ce1732a1443f5e89ed
- https://git.kernel.org/stable/c/fccd685b32df5aaf6bad4381eeda216468e283f0
- https://git.kernel.org/stable/c/820e501be8aee4b365d218d83227b314309c5fda
- https://git.kernel.org/stable/c/82ac903e0b519849647657b8c48d21237ada06a2
- https://git.kernel.org/stable/c/3db50ceeacb52806d8fe86fb1dfe944df0b9f789
- https://git.kernel.org/stable/c/742b04d0550b0ec89dcbc99537ec88653bd1ad90
ADP enrichment
No English description supplied.
No references supplied.