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Revision 77788775c7132a8d93c6930ab1bd84fc743c7cb7 authored by Jens Axboe on 29 December 2020, 17:50:46 UTC, committed by Jens Axboe on 29 December 2020, 18:00:36 UTC 
io_uring: don't assume mm is constant across submits
 
If we COW the identity, we assume that ->mm never changes. But this
isn't true of multiple processes end up sharing the ring. Hence treat
id->mm like like any other process compontent when it comes to the
identity mapping. This is pretty trivial, just moving the existing grab
into io_grab_identity(), and including a check for the match.

Cc: stable@vger.kernel.org # 5.10
Fixes: 1e6fa5216a0e ("io_uring: COW io_identity on mismatch")
Reported-by: Christian Brauner <christian.brauner@ubuntu.com>:
Tested-by: Christian Brauner <christian.brauner@ubuntu.com>:
Signed-off-by: Jens Axboe <axboe@kernel.dk>
1 parent 5c8fe58
Raw File
Makefile.kasan 
# SPDX-License-Identifier: GPL-2.0
CFLAGS_KASAN_NOSANITIZE := -fno-builtin
KASAN_SHADOW_OFFSET ?= $(CONFIG_KASAN_SHADOW_OFFSET)

ifdef CONFIG_KASAN_GENERIC

ifdef CONFIG_KASAN_INLINE
	call_threshold := 10000
else
	call_threshold := 0
endif

CFLAGS_KASAN_MINIMAL := -fsanitize=kernel-address

cc-param = $(call cc-option, -mllvm -$(1), $(call cc-option, --param $(1)))

# -fasan-shadow-offset fails without -fsanitize
CFLAGS_KASAN_SHADOW := $(call cc-option, -fsanitize=kernel-address \
			-fasan-shadow-offset=$(KASAN_SHADOW_OFFSET), \
			$(call cc-option, -fsanitize=kernel-address \
			-mllvm -asan-mapping-offset=$(KASAN_SHADOW_OFFSET)))

ifeq ($(strip $(CFLAGS_KASAN_SHADOW)),)
	CFLAGS_KASAN := $(CFLAGS_KASAN_MINIMAL)
else
	# Now add all the compiler specific options that are valid standalone
	CFLAGS_KASAN := $(CFLAGS_KASAN_SHADOW) \
	 $(call cc-param,asan-globals=1) \
	 $(call cc-param,asan-instrumentation-with-call-threshold=$(call_threshold)) \
	 $(call cc-param,asan-stack=$(CONFIG_KASAN_STACK)) \
	 $(call cc-param,asan-instrument-allocas=1)
endif

endif # CONFIG_KASAN_GENERIC

ifdef CONFIG_KASAN_SW_TAGS

ifdef CONFIG_KASAN_INLINE
    instrumentation_flags := -mllvm -hwasan-mapping-offset=$(KASAN_SHADOW_OFFSET)
else
    instrumentation_flags := -mllvm -hwasan-instrument-with-calls=1
endif

CFLAGS_KASAN := -fsanitize=kernel-hwaddress \
		-mllvm -hwasan-instrument-stack=$(CONFIG_KASAN_STACK) \
		-mllvm -hwasan-use-short-granules=0 \
		$(instrumentation_flags)

endif # CONFIG_KASAN_SW_TAGS

export CFLAGS_KASAN CFLAGS_KASAN_NOSANITIZE
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