From: Yuqi Xu <xuyuqiabc@gmail.com> stable inclusion from stable-v6.6.160 commit eebc70f132041b35da9ec74d5d395083125289b2 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/20518 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- commit 15fb9e3cea55fbc378261ce35a32b0f8828f0000 upstream. The fixed_rate_idx debugfs file is a plain u32 attribute, so any value can be written to it. minstrel_ht_update_stats() then copies the value into mi->max_tp_rate[] and mi->max_prob_rate, and minstrel_ht_set_rate() uses MI_RATE_GROUP()/MI_RATE_IDX() to index minstrel_mcs_groups[] (42 entries) and mi->groups[].rates[] (10 entries) with it. Writing e.g. 65535 selects group 4095 and rate index 15, far outside both arrays. The out-of-bounds entries are dereferenced and updated as struct minstrel_rate_stats (retry counts, etc.), so the invalid index corrupts adjacent kernel memory. With CONFIG_UBSAN_BOUNDS the access is reported as an array-index-out-of-bounds in minstrel_ht_set_rate(). Only a valid group/rate pair, or U32_MAX to disable fixed rate processing, can be used safely, so reject any other value when the debugfs file is written. The file is only reachable through a root-only debugfs mount, so this is not a privilege boundary. The out-of-bounds access is still a bug that must not be reachable through a writable debugfs attribute. Fixes: 24f7580e852b ("minstrel_ht: fixed rate mode through debugfs") Cc: stable@vger.kernel.org Reported-by: Vega <vega@nebusec.ai> Assisted-by: LLM Signed-off-by: Yuqi Xu <xuyuqiabc@gmail.com> Reviewed-by: Ren Wei <weir@nebusec.ai> Link: https://patch.msgid.link/288e6f6d30dc82ff40da502755e6666982f6b735.1789798000... Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yi Yang <yiyang13@huawei.com> --- net/mac80211/rc80211_minstrel_ht.c | 30 ++++++++++++++++++++++++++++-- 1 file changed, 28 insertions(+), 2 deletions(-) diff --git a/net/mac80211/rc80211_minstrel_ht.c b/net/mac80211/rc80211_minstrel_ht.c index 34eee00dac4f..737b1ad04366 100644 --- a/net/mac80211/rc80211_minstrel_ht.c +++ b/net/mac80211/rc80211_minstrel_ht.c @@ -7,6 +7,7 @@ #include <linux/types.h> #include <linux/skbuff.h> #include <linux/debugfs.h> +#include <linux/limits.h> #include <linux/random.h> #include <linux/moduleparam.h> #include <linux/ieee80211.h> @@ -2015,14 +2016,39 @@ minstrel_ht_alloc(struct ieee80211_hw *hw) } #ifdef CONFIG_MAC80211_DEBUGFS +static int minstrel_ht_fixed_rate_idx_get(void *data, u64 *val) +{ + *val = *(u32 *)data; + return 0; +} + +static int minstrel_ht_fixed_rate_idx_set(void *data, u64 val) +{ + u32 idx = val; + + /* U32_MAX is the default and keeps fixed rate processing disabled */ + if (val != U32_MAX && + (val > U16_MAX || + MI_RATE_GROUP(idx) >= ARRAY_SIZE(minstrel_mcs_groups) || + MI_RATE_IDX(idx) >= MCS_GROUP_RATES)) + return -EINVAL; + + *(u32 *)data = idx; + return 0; +} + +DEFINE_DEBUGFS_ATTRIBUTE(minstrel_ht_fixed_rate_idx_fops, + minstrel_ht_fixed_rate_idx_get, + minstrel_ht_fixed_rate_idx_set, "%llu\n"); + static void minstrel_ht_add_debugfs(struct ieee80211_hw *hw, void *priv, struct dentry *debugfsdir) { struct minstrel_priv *mp = priv; mp->fixed_rate_idx = (u32) -1; - debugfs_create_u32("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, - &mp->fixed_rate_idx); + debugfs_create_file("fixed_rate_idx", S_IRUGO | S_IWUGO, debugfsdir, + &mp->fixed_rate_idx, &minstrel_ht_fixed_rate_idx_fops); } #endif -- 2.25.1