RDMA/mlx5: Fix stack out-of-bounds read in cc_params debugfs

Summary

In the Linux kernel, the following vulnerability has been resolved: RDMA/mlx5: Fix stack out-of-bounds read in cc_params debugfs get_param() reads a congestion parameter as a u32 but formats it with the signed "%d" into an 11-byte stack buffer. A value with bit 31 set, such as 0x80000000, renders as "-2147483648\n" whose full length is 12. snprintf() stores only 11 bytes yet returns 12, so simple_read_from_buffer() treats 12 bytes as valid and reads one byte past lbuf[]. Size the buffer for the widest unsigned decimal, format with "%u" to match the u32, and use scnprintf() so the length passed to simple_read_from_buffer() reflects the bytes actually stored.

Timeline

1. Sep 17, 2026, 4:09 PM UTCCVE published
2. Oct 19, 2026, 9:03 AM UTCRecord last updated

Affected versions

• Linux Linux

  From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in 1c5b4f76cd73372c5a8a4c91c95d5a31f141e091; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in 06b62758f81e27ca4c81201c22e3436c6d9ac894; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in d809cf3f0ed9255abfc73c4730bcf187151422af; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in 0b0122fcc923a0271130f5fb71af2cd7e20434d9; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in ce8dfd32a33b578c3abf178f67b4c8d36854f041; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in 4599311e78e88c893ad551aca622de2bfdf1c31f; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in c75ee076fa09778a2f9602a972dade4a0b0785f7; From 4a2da0b8c0782816f3ae6846ae7942fcbb0f8172 · fixed in 03826bc1fa6c90405bf05831f2b501a8368dcd27

• Linux Linux

  4.14

• KernelLinux

  From 4.14.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8