lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-ID: <202409050957.7DD6B23EA@keescook> Date: Thu, 5 Sep 2024 09:58:25 -0700 From: Kees Cook <kees@...nel.org> To: Dmitry Antipov <dmantipov@...dex.ru> Cc: Johannes Berg <johannes.berg@...el.com>, Kalle Valo <kvalo@...nel.org>, linux-wireless@...r.kernel.org, linux-hardening@...r.kernel.org, lvc-project@...uxtesting.org Subject: Re: [PATCH] wifi: cfg80211: fix UBSAN noise in cfg80211_wext_siwscan() On Thu, Sep 05, 2024 at 06:04:00PM +0300, Dmitry Antipov wrote: > Looking at https://syzkaller.appspot.com/bug?extid=1a3986bbd3169c307819 > and running reproducer with CONFIG_UBSAN_BOUNDS, I've noticed the > following: > > [ T4985] UBSAN: array-index-out-of-bounds in net/wireless/scan.c:3479:25 > [ T4985] index 164 is out of range for type 'struct ieee80211_channel *[]' > <...skipped...> > [ T4985] Call Trace: > [ T4985] <TASK> > [ T4985] dump_stack_lvl+0x1c2/0x2a0 > [ T4985] ? __pfx_dump_stack_lvl+0x10/0x10 > [ T4985] ? __pfx__printk+0x10/0x10 > [ T4985] __ubsan_handle_out_of_bounds+0x127/0x150 > [ T4985] cfg80211_wext_siwscan+0x11a4/0x1260 > <...the rest is not too useful...> > > Even if we do 'creq->n_channels = n_channels' before 'creq->ssids = > (void *)&creq->channels[n_channels]', UBSAN treats the latter as > off-by-one error. Fix this by using pointer arithmetic rather than > an expression with explicit array indexing and use convenient > 'struct_size()' to simplify the math here and in 'kzalloc()' above. > > Fixes: 5ba63533bbf6 ("cfg80211: fix alignment problem in scan request") > Signed-off-by: Dmitry Antipov <dmantipov@...dex.ru> This looks correct -- the offset is based on the allocation base, not the array within the struct, so no array-out-of-bounds warning will happen. Reviewed-by: Kees Cook <kees@...nel.org> -- Kees Cook
Powered by blists - more mailing lists