From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx4++oyxM50XpG0kJa1BqS7OSx8iaP9EPO6qM9SzTTkVvA/1r7ll0mnJ41oGZUDFSW98cBmuM ARC-Seal: i=1; a=rsa-sha256; t=1523021592; cv=none; d=google.com; s=arc-20160816; b=Mo6mxyblis278tyckgBNhEZZ5IREj8tWl0wOvLo6Z5QG8ePwSOZ15AGL2KmLiVuoCx 02TkYzlABUFvjy+RBpb4bDnO+HnaRTpfGt/GIlnaOlMCvM6BEsMpo6QFrC6zqF3DsQqw GEe/WLvGBbCYgJbPJWy8uowqt5+QNBBnl11NsIMUKs/S81Zm2/pFefmQ7C2NaZtRrbjY R1K9r9tb5VQdKk9jtdqbYpYvLtoPzlpV0YSNd89Ft8gPS2RI3l1u/AotFsG2Hzybsau3 jTDzdXpfLC8zAr8c74EW7//GgqXvNzH8PjaH7MdPo8rSiNKUGatgyGebHrDRPpoM0CzN Lkyw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=ORpX67BtVal0nCgjEgRFoO1j+CS8LmUHxSaq6J5vgoI=; b=bN2qG+gRuCoZC3a45drIFwen1ZJNKGUd4lIr5hmfTKriNAPoZy9ebiNy4h7D5sPI9j 9BTO3SY8sZB5TaJemxRCB8S8vXPF9yX0IwnR1SG6rZ9aC/Lt2B8gBcrCInflS8dFioEP ZZAOLOnD3yS3iLesDTmyhit462Ulg0lzZOGhv2M3qxxYzai8lWzkNnhnp5N0ARM/sie1 qvi48LzoTxMaRJFfuJR9qb6gpA8aJGyKIyQ/ZE3gkmC6tKUceMlnL5ATd0ciFk4YQUrm kkBLuzWZi0u33Eiudb/LTLzjCAlt5qDuAOD7Q4DRjRoYYFwXOy1vJ42N+xo3HVcjkuwi vmzQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 90.92.61.202 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Linus Walleij , Boris Brezillon Subject: [PATCH 4.9 002/102] mtd: jedec_probe: Fix crash in jedec_read_mfr() Date: Fri, 6 Apr 2018 15:22:43 +0200 Message-Id: <20180406084331.842625333@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180406084331.507038179@linuxfoundation.org> References: <20180406084331.507038179@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1597003460655922984?= X-GMAIL-MSGID: =?utf-8?q?1597003888993192652?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Linus Walleij commit 87a73eb5b56fd6e07c8e499fe8608ef2d8912b82 upstream. It turns out that the loop where we read manufacturer jedec_read_mfd() can under some circumstances get a CFI_MFR_CONTINUATION repeatedly, making the loop go over all banks and eventually hit the end of the map and crash because of an access violation: Unable to handle kernel paging request at virtual address c4980000 pgd = (ptrval) [c4980000] *pgd=03808811, *pte=00000000, *ppte=00000000 Internal error: Oops: 7 [#1] PREEMPT ARM CPU: 0 PID: 1 Comm: swapper Not tainted 4.16.0-rc1+ #150 Hardware name: Gemini (Device Tree) PC is at jedec_probe_chip+0x6ec/0xcd0 LR is at 0x4 pc : [] lr : [<00000004>] psr: 60000013 sp : c382dd18 ip : 0000ffff fp : 00000000 r10: c0626388 r9 : 00020000 r8 : c0626340 r7 : 00000000 r6 : 00000001 r5 : c3a71afc r4 : c382dd70 r3 : 00000001 r2 : c4900000 r1 : 00000002 r0 : 00080000 Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none Control: 0000397f Table: 00004000 DAC: 00000053 Process swapper (pid: 1, stack limit = 0x(ptrval)) Fix this by breaking the loop with a return 0 if the offset exceeds the map size. Fixes: 5c9c11e1c47c ("[MTD] [NOR] Add support for flash chips with ID in bank other than 0") Cc: Signed-off-by: Linus Walleij Signed-off-by: Boris Brezillon Signed-off-by: Greg Kroah-Hartman --- drivers/mtd/chips/jedec_probe.c | 2 ++ 1 file changed, 2 insertions(+) --- a/drivers/mtd/chips/jedec_probe.c +++ b/drivers/mtd/chips/jedec_probe.c @@ -1889,6 +1889,8 @@ static inline u32 jedec_read_mfr(struct do { uint32_t ofs = cfi_build_cmd_addr(0 + (bank << 8), map, cfi); mask = (1 << (cfi->device_type * 8)) - 1; + if (ofs >= map->size) + return 0; result = map_read(map, base + ofs); bank++; } while ((result.x[0] & mask) == CFI_MFR_CONTINUATION);