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

Browse source

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.

Fixes: 4a2da0b8c0 ("IB/mlx5: Add debug control parameters for congestion control")
Link: https://patch.msgid.link/20260726-get-param-leaks-kernel-stack-memory-v1-1-d61a4d39662d@nvidia.com
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

...

This commit is contained in:

Leon Romanovsky 2026-07-26 12:13:55 +03:00

parent 373f3716a2

commit 03826bc1fa

1 changed files with 2 additions and 4 deletions

Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL

Download patch file Download diff file Expand all files Collapse all files

6

drivers/infiniband/hw/mlx5/cong.c

View file