Merge tag 'nand/for-4.20' of git://git.infradead.org/linux-mtd into mtd/next

NAND core changes:
- Two batchs of cleanups of the NAND API, including:
  * Deprecating a lot of interfaces (now replaced by ->exec_op()).
  * Moving code in separate drivers (JEDEC, ONFI), in private files
    (internals), in platform drivers, etc.
  * Functions/structures reordering.
  * Exclusive use of the nand_chip structure instead of the MTD one
    all across the subsystem.
- Addition of the nand_wait_readrdy/rdy_op() helpers.

Raw NAND controllers drivers changes:
- Various coccinelle patches.
- Marvell:
  * Use regmap_update_bits() for syscon access.
  * More documentation.
  * BCH failure path rework.
  * More layouts to be supported.
  * IRQ handler complete() condition fixed.
- Fsl_ifc:
  * SRAM initialization fixed for newer controller versions.
- Denali:
  * Fix licenses mismatch and use a SPDX tag.
  * Set SPARE_AREA_SKIP_BYTES register to 8 if unset.
- Qualcomm:
  * Do not include dma-direct.h.
- Docg4:
  * Removed.
- Ams-delta:
  * Use of a GPIO lookup table
  * Internal machinery changes.

Raw NAND chip drivers changes:
- Toshiba:
  * Add support for Toshiba memory BENAND
  * Pass a single nand_chip object to the status helper.
- ESMT:
  * New driver to retrieve the ECC requirements from the 5th ID byte.

1 files changed, 17 insertions, 3 deletions

diff --git a/arch/x86/kernel/dumpstack.c b/arch/x86/kernel/dumpstack.c
index 9c8652974f8e..f56895106ccf 100644
--- a/arch/x86/kernel/dumpstack.c
+++ b/arch/x86/kernel/dumpstack.c
@@ -17,6 +17,7 @@
 #include <linux/bug.h>
 #include <linux/nmi.h>
 #include <linux/sysfs.h>
+#include <linux/kasan.h>
 
 #include <asm/cpu_entry_area.h>
 #include <asm/stacktrace.h>
@@ -89,14 +90,24 @@ static void printk_stack_address(unsigned long address, int reliable,
  * Thus, the 2/3rds prologue and 64 byte OPCODE_BUFSIZE is just a random
  * guesstimate in attempt to achieve all of the above.
  */
-void show_opcodes(u8 *rip, const char *loglvl)
+void show_opcodes(struct pt_regs *regs, const char *loglvl)
 {
 #define PROLOGUE_SIZE 42
 #define EPILOGUE_SIZE 21
 #define OPCODE_BUFSIZE (PROLOGUE_SIZE + 1 + EPILOGUE_SIZE)
 	u8 opcodes[OPCODE_BUFSIZE];
+	unsigned long prologue = regs->ip - PROLOGUE_SIZE;
+	bool bad_ip;
 
-	if (probe_kernel_read(opcodes, rip - PROLOGUE_SIZE, OPCODE_BUFSIZE)) {
+	/*
+	 * Make sure userspace isn't trying to trick us into dumping kernel
+	 * memory by pointing the userspace instruction pointer at it.
+	 */
+	bad_ip = user_mode(regs) &&
+		__chk_range_not_ok(prologue, OPCODE_BUFSIZE, TASK_SIZE_MAX);
+
+	if (bad_ip || probe_kernel_read(opcodes, (u8 *)prologue,
+					OPCODE_BUFSIZE)) {
 		printk("%sCode: Bad RIP value.\n", loglvl);
 	} else {
 		printk("%sCode: %" __stringify(PROLOGUE_SIZE) "ph <%02x> %"
@@ -112,7 +123,7 @@ void show_ip(struct pt_regs *regs, const char *loglvl)
 #else
 	printk("%sRIP: %04x:%pS\n", loglvl, (int)regs->cs, (void *)regs->ip);
 #endif
-	show_opcodes((u8 *)regs->ip, loglvl);
+	show_opcodes(regs, loglvl);
 }
 
 void show_iret_regs(struct pt_regs *regs)
@@ -346,7 +357,10 @@ void oops_end(unsigned long flags, struct pt_regs *regs, int signr)
 	 * We're not going to return, but we might be on an IST stack or
 	 * have very little stack space left.  Rewind the stack and kill
 	 * the task.
+	 * Before we rewind the stack, we have to tell KASAN that we're going to
+	 * reuse the task stack and that existing poisons are invalid.
 	 */
+	kasan_unpoison_task_stack(current);
 	rewind_stack_do_exit(signr);
 }
 NOKPROBE_SYMBOL(oops_end);