Description
In the Linux kernel, the following vulnerability has been resolved: net: skmsg: preserve sg.copy across SG transforms The sk_msg sg.copy bitmap is part of the scatterlist entry ownership state. A set bit tells sk_msg_compute_data_pointers() not to expose the entry through writable BPF ctx->data. This protects entries backed by pages that are not private to the sk_msg, such as splice-backed file page-cache pages. Several sk_msg transform paths move, copy, split, or compact msg->sg.data[] entries without moving the matching sg.copy bit. This can make an externally backed entry arrive at a new slot with a clear copy bit. A later SK_MSG verdict can then expose sg_virt(sge) as writable ctx->data and BPF stores can modify the original page cache. Keep sg.copy synchronized with sg.data[] whenever entries are transferred, shifted, split, or copied into a new sk_msg. Clear the bit when an entry is replaced by a newly allocated private page or freed. This covers the BPF pull/push/pop helpers, sk_msg_shift_left/right(), sk_msg_xfer(), and tls_split_open_record(), including the partial tail entry created during TLS open-record splitting.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
Linux Linux
Default version status: unaffected
d3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < f126eed589eec6f201405abbc398844042ef6d57affectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 31a110642b5fb5e61940cbcfb503445ac4f28017affectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 9bb86d8184b37503816150c4a6ad3c17dfdbe827affectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 0eb4c16c4adb262763bda870a8ed38a1a9dec7ecaffectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < d22cc92bc41290e5783a72375e0843d9435f6001affectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 1acdd14c0990dd1cd4b6534f00366d2e6dfce05faffectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 21ed9540a8e1906dfcbc1bb82ba9b4de4fa4bd6daffectedd3b18ad31f93d0b6bae105c679018a1ba7daa9ca to < 406e8a651a7b854c41fecd5117bb282b3a6c2c6baffected
Linux Linux
Default version status: affected
4.20affected0 to < 4.20unaffected5.10.261 to ≤ 5.10.*unaffected5.15.212 to ≤ 5.15.*unaffected6.1.177 to ≤ 6.1.*unaffected6.6.144 to ≤ 6.6.*unaffected6.12.95 to ≤ 6.12.*unaffected6.18.38 to ≤ 6.18.*unaffected7.1.3 to ≤ 7.1.*unaffected7.2 to ≤ *unaffected
References
- https://git.kernel.org/stable/c/f126eed589eec6f201405abbc398844042ef6d57 ↗
- https://git.kernel.org/stable/c/31a110642b5fb5e61940cbcfb503445ac4f28017 ↗
- https://git.kernel.org/stable/c/9bb86d8184b37503816150c4a6ad3c17dfdbe827 ↗
- https://git.kernel.org/stable/c/0eb4c16c4adb262763bda870a8ed38a1a9dec7ec ↗
- https://git.kernel.org/stable/c/d22cc92bc41290e5783a72375e0843d9435f6001 ↗
- https://git.kernel.org/stable/c/1acdd14c0990dd1cd4b6534f00366d2e6dfce05f ↗
- https://git.kernel.org/stable/c/21ed9540a8e1906dfcbc1bb82ba9b4de4fa4bd6d ↗
- https://git.kernel.org/stable/c/406e8a651a7b854c41fecd5117bb282b3a6c2c6b ↗