From 4bef9320f7a9b1cdcb0223fccf85d933a13178fb Mon Sep 17 00:00:00 2001 From: Zekun Shen 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 Signed-off-by: Kalle Valo Link: https://lore.kernel.org/r/YM3xKsQJ0Hw2hjrc@Zekuns-MBP-16.fios-router.home Signed-off-by: Sasha Levin --- 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 76385834a7de..694a58b1e995 100644 --- a/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c +++ b/drivers/net/wireless/ath/ath9k/ar9003_eeprom.c @@ -3346,7 +3346,8 @@ 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;