Description (CNA)
In the Linux kernel, the following vulnerability has been resolved: ipv6: rpl: fix hdrlen overflow in ipv6_rpl_srh_decompress() ipv6_rpl_srh_decompress() computes: outhdr->hdrlen = (((n + 1) * sizeof(struct in6_addr)) >> 3); hdrlen is __u8. For n >= 127 the result exceeds 255 and silently truncates. With n=127 (cmpri=15, cmpre=15, pad=0, hdrlen=16): (128 * 16) >> 3 = 256, truncated to 0 as __u8 The caller in ipv6_rpl_srh_rcv() then places the compressed header at buf + ((ohdr->hdrlen + 1) << 3). With hdrlen=0 this is buf + 8, but the decompressed region occupies buf[0..2055] (8-byte header plus 128 full addresses). The compressed header overlaps the decompressed data, and ipv6_rpl_srh_compress() writes into this overlap, corrupting the routing header of the forwarded packet. The existing guard at exthdrs.c:546 checks (n + 1) > 255, which prevents n+1 from overflowing unsigned char (the segments_left field), but does not prevent the computed hdrlen from overflowing __u8. n=127 passes because 128 <= 255, yet hdrlen=256 does not fit. Tighten the bound to (n + 1) > 127. This caps n at 126, giving hdrlen = (127 * 16) >> 3 = 254, which fits in __u8. The compressed header then lands at buf + ((254 + 1) << 3) = buf + 2040, exactly past the decompressed region (buf[0..2039]). No overlap. 127 segments is well beyond any realistic RPL deployment.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before 75b3680047bf09af8e7e471a7a6ddf2ce5847f56; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before fd238c51b0fa5390cceca9f1ac5a9ffda8063eed; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before 3618b34942b76471d044369bfd30d58c39068bf1; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before 97e06791368c01f0ad2a4b3269c2abe19485ca32; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before de02fc049352af5a9595f015511222d0a85c326b; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before 6fe1cb312038516cb4d9fa089d700af7059f1a64; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before c0487a9c1e116cf349e2d1f302d9019670460858; affected 8610c7c6e3bd647ff98d21c8bc0580e77bc2f8b3 before 9d5e7a46a9f6d8f503b41bfefef70659845f1679 |
| Linux / Linux | affected 5.7; unaffected 0 before 5.7; 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/75b3680047bf09af8e7e471a7a6ddf2ce5847f56
- https://git.kernel.org/stable/c/fd238c51b0fa5390cceca9f1ac5a9ffda8063eed
- https://git.kernel.org/stable/c/3618b34942b76471d044369bfd30d58c39068bf1
- https://git.kernel.org/stable/c/97e06791368c01f0ad2a4b3269c2abe19485ca32
- https://git.kernel.org/stable/c/de02fc049352af5a9595f015511222d0a85c326b
- https://git.kernel.org/stable/c/6fe1cb312038516cb4d9fa089d700af7059f1a64
- https://git.kernel.org/stable/c/c0487a9c1e116cf349e2d1f302d9019670460858
- https://git.kernel.org/stable/c/9d5e7a46a9f6d8f503b41bfefef70659845f1679
ADP enrichment
No English description supplied.
No references supplied.