From f41f0adde4178b1b68ff004cba7e2038debb7b13 Mon Sep 17 00:00:00 2001 From: Zekun Shen <bruceshenzk@gmail.com> Date: Sat, 19 Jun 2021 09:29:14 -0400 Subject: [PATCH] ath9k: fix OOB read ar9300_eeprom_restore_internal [ Upstream commit 23151b9ae79e3bc4f6a0c4cd3a7f355f68dad128 ] Bad header can have large length field which can cause OOB. cptr is the last bytes for read, and the eeprom is parsed from high to low address. The OOB, triggered by the condition length > cptr could cause memory error with a read on negative index. There are some sanity check around length, but it is not compared with cptr (the remaining bytes). Here, the corrupted/bad EEPROM can cause panic. I was able to reproduce the crash, but I cannot find the log and the reproducer now. After I applied the patch, the bug is no longer reproducible. Signed-off-by: Zekun Shen <bruceshenzk@gmail.com> Signed-off-by: Kalle Valo <kvalo@codeaurora.org> Link: https://lore.kernel.org/r/YM3xKsQJ0Hw2hjrc@Zekuns-MBP-16.fios-router.home Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/net/wireless/ath/ath9k/ar9003_eeprom.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c index c876dc2437b0d1..96e1f54cccaf6d 100644 --- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c +++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c @@ -3345,7 +3345,8 @@ found: "Found block at %x: code=%d ref=%d length=%d major=%d minor=%d\n", cptr, code, reference, length, major, minor); if ((!AR_SREV_9485(ah) && length >= 1024) || - (AR_SREV_9485(ah) && length > EEPROM_DATA_LEN_9485)) { + (AR_SREV_9485(ah) && length > EEPROM_DATA_LEN_9485) || + (length > cptr)) { ath_dbg(common, EEPROM, "Skipping bad header\n"); cptr -= COMP_HDR_LEN; continue; -- GitLab