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From: Sasha Levin <sashal@kernel.org>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: Peter Zijlstra <peterz@infradead.org>,
	Randy Dunlap <rdunlap@infradead.org>,
	Linus Torvalds <torvalds@linux-foundation.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	luto@kernel.org, Ingo Molnar <mingo@kernel.org>,
	Sasha Levin <sashal@kernel.org>
Subject: [PATCH AUTOSEL 4.9 036/114] mm/uaccess: Use 'unsigned long' to placate UBSAN warnings on older GCC versions
Date: Wed, 22 May 2019 15:28:59 -0400	[thread overview]
Message-ID: <20190522193017.26567-36-sashal@kernel.org> (raw)
In-Reply-To: <20190522193017.26567-1-sashal@kernel.org>

From: Peter Zijlstra <peterz@infradead.org>

[ Upstream commit 29da93fea3ea39ab9b12270cc6be1b70ef201c9e ]

Randy reported objtool triggered on his (GCC-7.4) build:

  lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x315: call to __ubsan_handle_add_overflow() with UACCESS enabled
  lib/strnlen_user.o: warning: objtool: strnlen_user()+0x337: call to __ubsan_handle_sub_overflow() with UACCESS enabled

This is due to UBSAN generating signed-overflow-UB warnings where it
should not. Prior to GCC-8 UBSAN ignored -fwrapv (which the kernel
uses through -fno-strict-overflow).

Make the functions use 'unsigned long' throughout.

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org> # build-tested
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: luto@kernel.org
Link: http://lkml.kernel.org/r/20190424072208.754094071@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 lib/strncpy_from_user.c | 5 +++--
 lib/strnlen_user.c      | 4 ++--
 2 files changed, 5 insertions(+), 4 deletions(-)

diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c
index 7e35fc450c5bb..5a07f19059c36 100644
--- a/lib/strncpy_from_user.c
+++ b/lib/strncpy_from_user.c
@@ -22,10 +22,11 @@
  * hit it), 'max' is the address space maximum (and we return
  * -EFAULT if we hit it).
  */
-static inline long do_strncpy_from_user(char *dst, const char __user *src, long count, unsigned long max)
+static inline long do_strncpy_from_user(char *dst, const char __user *src,
+					unsigned long count, unsigned long max)
 {
 	const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
-	long res = 0;
+	unsigned long res = 0;
 
 	/*
 	 * Truncate 'max' to the user-specified limit, so that
diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c
index 8e105ed4df12b..9ff4f3bbb1aae 100644
--- a/lib/strnlen_user.c
+++ b/lib/strnlen_user.c
@@ -27,7 +27,7 @@
 static inline long do_strnlen_user(const char __user *src, unsigned long count, unsigned long max)
 {
 	const struct word_at_a_time constants = WORD_AT_A_TIME_CONSTANTS;
-	long align, res = 0;
+	unsigned long align, res = 0;
 	unsigned long c;
 
 	/*
@@ -41,7 +41,7 @@ static inline long do_strnlen_user(const char __user *src, unsigned long count,
 	 * Do everything aligned. But that means that we
 	 * need to also expand the maximum..
 	 */
-	align = (sizeof(long) - 1) & (unsigned long)src;
+	align = (sizeof(unsigned long) - 1) & (unsigned long)src;
 	src -= align;
 	max += align;
 
-- 
2.20.1


  parent reply	other threads:[~2019-05-22 19:35 UTC|newest]

Thread overview: 42+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-22 19:28 [PATCH AUTOSEL 4.9 001/114] gfs2: Fix lru_count going negative Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 002/114] cxgb4: Fix error path in cxgb4_init_module Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 003/114] mmc: core: Verify SD bus width Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 004/114] dmaengine: tegra210-dma: free dma controller in remove() Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 005/114] net: ena: gcc 8: fix compilation warning Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 006/114] orangefs: truncate before updating size Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 007/114] ASoC: hdmi-codec: unlock the device on startup errors Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 008/114] powerpc/boot: Fix missing check of lseek() return value Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 009/114] ASoC: imx: fix fiq dependencies Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 010/114] spi: pxa2xx: fix SCR (divisor) calculation Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 011/114] brcm80211: potential NULL dereference in brcmf_cfg80211_vndr_cmds_dcmd_handler() Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 012/114] ARM: vdso: Remove dependency with the arch_timer driver internals Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 013/114] arm64: Fix compiler warning from pte_unmap() with -Wunused-but-set-variable Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 014/114] sched/cpufreq: Fix kobject memleak Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 015/114] scsi: qla2xxx: Fix a qla24xx_enable_msix() error path Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 016/114] iwlwifi: pcie: don't crash on invalid RX interrupt Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 017/114] rtc: 88pm860x: prevent use-after-free on device remove Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 018/114] w1: fix the resume command API Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 019/114] dmaengine: pl330: _stop: clear interrupt status Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 020/114] mac80211/cfg80211: update bss channel on channel switch Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 021/114] driver core: platform: Fix the usage of platform device name(pdev->name) Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 022/114] ASoC: fsl_sai: Update is_slave_mode with correct value Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 023/114] mwifiex: prevent an array overflow Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 024/114] net: cw1200: fix a NULL pointer dereference Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 025/114] at76c50x-usb: Don't register led_trigger if usb_register_driver failed Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 026/114] ssb: Fix possible NULL pointer dereference in ssb_host_pcmcia_exit Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 027/114] crypto: sun4i-ss - Fix invalid calculation of hash end Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 028/114] bcache: return error immediately in bch_journal_replay() Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 029/114] bcache: fix failure in journal relplay Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 030/114] bcache: add failure check to run_cache_set() for journal replay Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 031/114] bcache: avoid clang -Wunintialized warning Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 032/114] RDMA/cma: Consider scope_id while binding to ipv6 ll address Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 033/114] x86/build: Move _etext to actual end of .text Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 034/114] smpboot: Place the __percpu annotation correctly Sasha Levin
2019-05-22 19:28 ` [PATCH AUTOSEL 4.9 035/114] x86/mm: Remove in_nmi() warning from 64-bit implementation of vmalloc_fault() Sasha Levin
2019-05-22 19:28 ` Sasha Levin [this message]
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 037/114] HID: logitech-hidpp: use RAP instead of FAP to get the protocol version Sasha Levin
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 038/114] pinctrl: pistachio: fix leaked of_node references Sasha Levin
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 039/114] dmaengine: at_xdmac: remove BUG_ON macro in tasklet Sasha Levin
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 040/114] media: coda: clear error return value before picture run Sasha Levin
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 041/114] media: ov6650: Move v4l2_clk_get() to ov6650_video_probe() helper Sasha Levin
2019-05-22 19:29 ` [PATCH AUTOSEL 4.9 042/114] media: au0828: stop video streaming only when last user stops Sasha Levin

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