CVE-2026-89724media: vicodec: fix out-of-bounds write in FWHT encoder

Official description

In the Linux kernel, the following vulnerability has been resolved: media: vicodec: fix out-of-bounds write in FWHT encoder vidioc_s_fmt_vid_out() sizes the encoder CAPTURE buffer from the compressed descriptor pixfmt_fwht, whose sizeimage_mult is 3: coded_w * coded_h * 3 + sizeof(struct fwht_cframe_hdr). fwht_encode_frame() encodes one plane per component, and an incompressible plane takes the FWHT_FRAME_UNENCODED path in encode_plane(), copying the plane verbatim. For a 4-component pixel format all four planes are full resolution (width_div == height_div == 1), so a frame that forces every plane through the unencoded fallback writes sizeof(struct fwht_cframe_hdr) + 4 * coded_w * coded_h bytes, overrunning the plane by coded_w * coded_h, which can result in corruption of adjacent kernel heap memory. Bump pixfmt_fwht.sizeimage_mult from 3 to 4, matching the largest components_num among the supported raw formats, so the capture buffer is always large enough for the unencoded fallback.

Affected packages & fixed versions

Affected products (as reported)

References

• https://git.kernel.org/stable/c/f7ae26c100a6c26c2a166d2c41e73188067b36bd
• https://git.kernel.org/stable/c/6ea647e76c44387d5c1c635df4604c2154d9060e
• https://git.kernel.org/stable/c/d40838a63f2bd6a3df0a6cdd8ff1d5c6366e8fff
• https://git.kernel.org/stable/c/e21cccc29b840930cd9dcfdf1139658063a681af
• https://git.kernel.org/stable/c/84cfebf7f4229d748cca8eb9c4e1f1c4099d3ab7
• https://git.kernel.org/stable/c/8c14472431e27f13661d0db9d837156eaced0ecb
• https://git.kernel.org/stable/c/b95315ffc66b39856396c1043618bb4e4d5785ba
• https://git.kernel.org/stable/c/cf4500ebf6fb57bf4ab83c3dd349a40257dbe2a9