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a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:in-reply-to:message-id:mime-version :references:subject:from:to:cc; bh=sdkgj896Qo+AFN+zvttnZapcO4bCa1e5ImK6MurFn1k=; b=DhjS0jOcZLtXTbwQONcE3OmcSzr0SixIW+Y2h/+BIAWKXh7vvNx9hTsvJqpnSiNkKp D7wgI2ce8ZPv9X7DPrCOVR+u7qYItSHCeC6+LiPhKmAvDi9GafLZeMQnSEgWWk4OWRzP Qqxrf64d/ksy70UtszIson16cKP+2oaiczpymCByu1TgzB7bT56cw/+Gq25T/0toXN1T l4usoBM2yZtwD340PSL6aqLXSIJk40EBFL6cCfz9jPjBJrRTQRqVYLO+dLum1gpDLRXr zYE12TKOf6kvkSVBYNhONSI9oXekTx3Rs6Q6b/OXhSTzzUeuJgFSi/tKAec0AqCrqVNz Ds3A== X-Gm-Message-State: AOAM531C26ztO/H89B/SlIh0s2oQU3MZvjJ6cXIwxHIPL3OimtKWRq7h qrJk2kR5cII2R1wglpGfJ6n8AS0T/NclHOgu X-Google-Smtp-Source: ABdhPJxDbLmIELc7j7WQJZu+Bpk80w6bKCbvSm27wbQqmOHDlPvAbZr77jAT0AHFGmy1CYo2Fg0HMKHW3zixhotB X-Received: from andreyknvl3.muc.corp.google.com ([2a00:79e0:15:13:edb8:b79c:2e20:e531]) (user=andreyknvl job=sendgmr) by 2002:a05:600c:21d2:: with SMTP id x18mr4105351wmj.186.1612539579825; Fri, 05 Feb 2021 07:39:39 -0800 (PST) Date: Fri, 5 Feb 2021 16:39:10 +0100 In-Reply-To: Message-Id: <3917dc59e3dbf99b2929a1e20d41df0c5930e026.1612538932.git.andreyknvl@google.com> Mime-Version: 1.0 References: X-Mailer: git-send-email 2.30.0.365.g02bc693789-goog Subject: [PATCH v2 09/12] kasan: ensure poisoning size alignment From: Andrey Konovalov To: Andrew Morton , Catalin Marinas , Vincenzo Frascino , Dmitry Vyukov , Alexander Potapenko , Marco Elver X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210205_103943_015718_F788BB91 X-CRM114-Status: GOOD ( 18.39 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Branislav Rankov , Andrey Konovalov , Kevin Brodsky , Will Deacon , linux-kernel@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org, linux-arm-kernel@lists.infradead.org, Andrey Ryabinin , Peter Collingbourne , Evgenii Stepanov Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org A previous changes d99f6a10c161 ("kasan: don't round_up too much") attempted to simplify the code by adding a round_up(size) call into kasan_poison(). While this allows to have less round_up() calls around the code, this results in round_up() being called multiple times. This patch removes round_up() of size from kasan_poison() and ensures that all callers round_up() the size explicitly. This patch also adds WARN_ON() alignment checks for address and size to kasan_poison() and kasan_unpoison(). Reviewed-by: Marco Elver Signed-off-by: Andrey Konovalov --- mm/kasan/common.c | 9 ++++++--- mm/kasan/kasan.h | 33 ++++++++++++++++++++------------- mm/kasan/shadow.c | 37 ++++++++++++++++++++++--------------- 3 files changed, 48 insertions(+), 31 deletions(-) diff --git a/mm/kasan/common.c b/mm/kasan/common.c index a8a67dca5e55..7ffb1e6de2ef 100644 --- a/mm/kasan/common.c +++ b/mm/kasan/common.c @@ -261,7 +261,8 @@ void __kasan_unpoison_object_data(struct kmem_cache *cache, void *object) void __kasan_poison_object_data(struct kmem_cache *cache, void *object) { - kasan_poison(object, cache->object_size, KASAN_KMALLOC_REDZONE); + kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE), + KASAN_KMALLOC_REDZONE); } /* @@ -348,7 +349,8 @@ static bool ____kasan_slab_free(struct kmem_cache *cache, void *object, return true; } - kasan_poison(object, cache->object_size, KASAN_KMALLOC_FREE); + kasan_poison(object, round_up(cache->object_size, KASAN_GRANULE_SIZE), + KASAN_KMALLOC_FREE); if ((IS_ENABLED(CONFIG_KASAN_GENERIC) && !quarantine)) return false; @@ -490,7 +492,8 @@ static void *____kasan_kmalloc(struct kmem_cache *cache, const void *object, /* Poison the aligned part of the redzone. */ redzone_start = round_up((unsigned long)(object + size), KASAN_GRANULE_SIZE); - redzone_end = (unsigned long)object + cache->object_size; + redzone_end = round_up((unsigned long)(object + cache->object_size), + KASAN_GRANULE_SIZE); kasan_poison((void *)redzone_start, redzone_end - redzone_start, KASAN_KMALLOC_REDZONE); diff --git a/mm/kasan/kasan.h b/mm/kasan/kasan.h index 6a2882997f23..98f70ffc9e1c 100644 --- a/mm/kasan/kasan.h +++ b/mm/kasan/kasan.h @@ -321,30 +321,37 @@ static inline u8 kasan_random_tag(void) { return 0; } #ifdef CONFIG_KASAN_HW_TAGS -static inline void kasan_poison(const void *address, size_t size, u8 value) +static inline void kasan_poison(const void *addr, size_t size, u8 value) { - address = kasan_reset_tag(address); + addr = kasan_reset_tag(addr); /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(address)) + if (is_kfence_address(addr)) return; - hw_set_mem_tag_range((void *)address, - round_up(size, KASAN_GRANULE_SIZE), value); + if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) + return; + if (WARN_ON(size & KASAN_GRANULE_MASK)) + return; + + hw_set_mem_tag_range((void *)addr, size, value); } -static inline void kasan_unpoison(const void *address, size_t size) +static inline void kasan_unpoison(const void *addr, size_t size) { - u8 tag = get_tag(address); + u8 tag = get_tag(addr); - address = kasan_reset_tag(address); + addr = kasan_reset_tag(addr); /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(address)) + if (is_kfence_address(addr)) return; - hw_set_mem_tag_range((void *)address, - round_up(size, KASAN_GRANULE_SIZE), tag); + if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) + return; + size = round_up(size, KASAN_GRANULE_SIZE); + + hw_set_mem_tag_range((void *)addr, size, tag); } static inline bool kasan_byte_accessible(const void *addr) @@ -361,7 +368,7 @@ static inline bool kasan_byte_accessible(const void *addr) /** * kasan_poison - mark the memory range as unaccessible * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE - * @size - range size + * @size - range size, must be aligned to KASAN_GRANULE_SIZE * @value - value that's written to metadata for the range * * The size gets aligned to KASAN_GRANULE_SIZE before marking the range. @@ -371,7 +378,7 @@ void kasan_poison(const void *addr, size_t size, u8 value); /** * kasan_unpoison - mark the memory range as accessible * @addr - range start address, must be aligned to KASAN_GRANULE_SIZE - * @size - range size + * @size - range size, can be unaligned * * For the tag-based modes, the @size gets aligned to KASAN_GRANULE_SIZE before * marking the range. diff --git a/mm/kasan/shadow.c b/mm/kasan/shadow.c index 1ed7817e4ee6..63f43443f5d7 100644 --- a/mm/kasan/shadow.c +++ b/mm/kasan/shadow.c @@ -69,7 +69,7 @@ void *memcpy(void *dest, const void *src, size_t len) return __memcpy(dest, src, len); } -void kasan_poison(const void *address, size_t size, u8 value) +void kasan_poison(const void *addr, size_t size, u8 value) { void *shadow_start, *shadow_end; @@ -78,55 +78,62 @@ void kasan_poison(const void *address, size_t size, u8 value) * some of the callers (e.g. kasan_poison_object_data) pass tagged * addresses to this function. */ - address = kasan_reset_tag(address); + addr = kasan_reset_tag(addr); /* Skip KFENCE memory if called explicitly outside of sl*b. */ - if (is_kfence_address(address)) + if (is_kfence_address(addr)) return; - size = round_up(size, KASAN_GRANULE_SIZE); - shadow_start = kasan_mem_to_shadow(address); - shadow_end = kasan_mem_to_shadow(address + size); + if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) + return; + if (WARN_ON(size & KASAN_GRANULE_MASK)) + return; + + shadow_start = kasan_mem_to_shadow(addr); + shadow_end = kasan_mem_to_shadow(addr + size); __memset(shadow_start, value, shadow_end - shadow_start); } EXPORT_SYMBOL(kasan_poison); #ifdef CONFIG_KASAN_GENERIC -void kasan_poison_last_granule(const void *address, size_t size) +void kasan_poison_last_granule(const void *addr, size_t size) { if (size & KASAN_GRANULE_MASK) { - u8 *shadow = (u8 *)kasan_mem_to_shadow(address + size); + u8 *shadow = (u8 *)kasan_mem_to_shadow(addr + size); *shadow = size & KASAN_GRANULE_MASK; } } #endif -void kasan_unpoison(const void *address, size_t size) +void kasan_unpoison(const void *addr, size_t size) { - u8 tag = get_tag(address); + u8 tag = get_tag(addr); /* * Perform shadow offset calculation based on untagged address, as * some of the callers (e.g. kasan_unpoison_object_data) pass tagged * addresses to this function. */ - address = kasan_reset_tag(address); + addr = kasan_reset_tag(addr); /* * Skip KFENCE memory if called explicitly outside of sl*b. Also note * that calls to ksize(), where size is not a multiple of machine-word * size, would otherwise poison the invalid portion of the word. */ - if (is_kfence_address(address)) + if (is_kfence_address(addr)) + return; + + if (WARN_ON((unsigned long)addr & KASAN_GRANULE_MASK)) return; - /* Unpoison round_up(size, KASAN_GRANULE_SIZE) bytes. */ - kasan_poison(address, size, tag); + /* Unpoison all granules that cover the object. */ + kasan_poison(addr, round_up(size, KASAN_GRANULE_SIZE), tag); /* Partially poison the last granule for the generic mode. */ if (IS_ENABLED(CONFIG_KASAN_GENERIC)) - kasan_poison_last_granule(address, size); + kasan_poison_last_granule(addr, size); } #ifdef CONFIG_MEMORY_HOTPLUG