From 6ccc72b87b83ece31c2a75bbe07f440b0378f7a9 Mon Sep 17 00:00:00 2001 From: Dave Young Date: Thu, 14 Aug 2014 17:15:27 +0800 Subject: lib: Add a generic cmdline parse function parse_option_str There should be a generic function to parse params like a=b,c Adding parse_option_str in lib/cmdline.c which will return true if there's specified option set in the params. Also updated efi=old_map parsing code to use the new function Signed-off-by: Dave Young Signed-off-by: Matt Fleming --- lib/cmdline.c | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) (limited to 'lib') diff --git a/lib/cmdline.c b/lib/cmdline.c index 76a712e6e20e..8f13cf73c2ec 100644 --- a/lib/cmdline.c +++ b/lib/cmdline.c @@ -160,3 +160,32 @@ unsigned long long memparse(const char *ptr, char **retptr) return ret; } EXPORT_SYMBOL(memparse); + +/** + * parse_option_str - Parse a string and check an option is set or not + * @str: String to be parsed + * @option: option name + * + * This function parses a string containing a comma-separated list of + * strings like a=b,c. + * + * Return true if there's such option in the string, or return false. + */ +bool parse_option_str(const char *str, const char *option) +{ + while (*str) { + if (!strncmp(str, option, strlen(option))) { + str += strlen(option); + if (!*str || *str == ',') + return true; + } + + while (*str && *str != ',') + str++; + + if (*str == ',') + str++; + } + + return false; +} -- cgit v1.2.3 From d4c5efdb97773f59a2b711754ca0953f24516739 Mon Sep 17 00:00:00 2001 From: Daniel Borkmann Date: Tue, 26 Aug 2014 23:16:35 -0400 Subject: random: add and use memzero_explicit() for clearing data zatimend has reported that in his environment (3.16/gcc4.8.3/corei7) memset() calls which clear out sensitive data in extract_{buf,entropy, entropy_user}() in random driver are being optimized away by gcc. Add a helper memzero_explicit() (similarly as explicit_bzero() variants) that can be used in such cases where a variable with sensitive data is being cleared out in the end. Other use cases might also be in crypto code. [ I have put this into lib/string.c though, as it's always built-in and doesn't need any dependencies then. ] Fixes kernel bugzilla: 82041 Reported-by: zatimend@hotmail.co.uk Signed-off-by: Daniel Borkmann Acked-by: Hannes Frederic Sowa Cc: Alexey Dobriyan Signed-off-by: Theodore Ts'o Cc: stable@vger.kernel.org --- drivers/char/random.c | 8 ++++---- include/linux/string.h | 5 +++-- lib/string.c | 16 ++++++++++++++++ 3 files changed, 23 insertions(+), 6 deletions(-) (limited to 'lib') diff --git a/drivers/char/random.c b/drivers/char/random.c index c18d41db83d8..8c86a95203a0 100644 --- a/drivers/char/random.c +++ b/drivers/char/random.c @@ -1106,7 +1106,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out) __mix_pool_bytes(r, hash.w, sizeof(hash.w)); spin_unlock_irqrestore(&r->lock, flags); - memset(workspace, 0, sizeof(workspace)); + memzero_explicit(workspace, sizeof(workspace)); /* * In case the hash function has some recognizable output @@ -1118,7 +1118,7 @@ static void extract_buf(struct entropy_store *r, __u8 *out) hash.w[2] ^= rol32(hash.w[2], 16); memcpy(out, &hash, EXTRACT_SIZE); - memset(&hash, 0, sizeof(hash)); + memzero_explicit(&hash, sizeof(hash)); } /* @@ -1175,7 +1175,7 @@ static ssize_t extract_entropy(struct entropy_store *r, void *buf, } /* Wipe data just returned from memory */ - memset(tmp, 0, sizeof(tmp)); + memzero_explicit(tmp, sizeof(tmp)); return ret; } @@ -1218,7 +1218,7 @@ static ssize_t extract_entropy_user(struct entropy_store *r, void __user *buf, } /* Wipe data just returned from memory */ - memset(tmp, 0, sizeof(tmp)); + memzero_explicit(tmp, sizeof(tmp)); return ret; } diff --git a/include/linux/string.h b/include/linux/string.h index d36977e029af..3b42b3732da6 100644 --- a/include/linux/string.h +++ b/include/linux/string.h @@ -132,7 +132,7 @@ int bprintf(u32 *bin_buf, size_t size, const char *fmt, ...) __printf(3, 4); #endif extern ssize_t memory_read_from_buffer(void *to, size_t count, loff_t *ppos, - const void *from, size_t available); + const void *from, size_t available); /** * strstarts - does @str start with @prefix? @@ -144,7 +144,8 @@ static inline bool strstarts(const char *str, const char *prefix) return strncmp(str, prefix, strlen(prefix)) == 0; } -extern size_t memweight(const void *ptr, size_t bytes); +size_t memweight(const void *ptr, size_t bytes); +void memzero_explicit(void *s, size_t count); /** * kbasename - return the last part of a pathname. diff --git a/lib/string.c b/lib/string.c index 992bf30af759..3a3120452a1d 100644 --- a/lib/string.c +++ b/lib/string.c @@ -604,6 +604,22 @@ void *memset(void *s, int c, size_t count) EXPORT_SYMBOL(memset); #endif +/** + * memzero_explicit - Fill a region of memory (e.g. sensitive + * keying data) with 0s. + * @s: Pointer to the start of the area. + * @count: The size of the area. + * + * memzero_explicit() doesn't need an arch-specific version as + * it just invokes the one of memset() implicitly. + */ +void memzero_explicit(void *s, size_t count) +{ + memset(s, 0, count); + OPTIMIZER_HIDE_VAR(s); +} +EXPORT_SYMBOL(memzero_explicit); + #ifndef __HAVE_ARCH_MEMCPY /** * memcpy - Copy one area of memory to another -- cgit v1.2.3 From c21e59d8dc04b2107bdb4ff0f412a9b7ae3349f3 Mon Sep 17 00:00:00 2001 From: Tony Battersby Date: Thu, 23 Oct 2014 15:10:21 -0400 Subject: lib/scatterlist: fix memory leak with scsi-mq Fix a memory leak with scsi-mq triggered by commands with large data transfer length. Fixes: c53c6d6a68b1 ("scatterlist: allow chaining to preallocated chunks") Cc: # 3.17.x Signed-off-by: Tony Battersby Reviewed-by: Martin K. Petersen Signed-off-by: Jens Axboe --- lib/scatterlist.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/scatterlist.c b/lib/scatterlist.c index 9cdf62f8accd..c9f2e8c6ccc9 100644 --- a/lib/scatterlist.c +++ b/lib/scatterlist.c @@ -203,10 +203,10 @@ void __sg_free_table(struct sg_table *table, unsigned int max_ents, } table->orig_nents -= sg_size; - if (!skip_first_chunk) { - free_fn(sgl, alloc_size); + if (skip_first_chunk) skip_first_chunk = false; - } + else + free_fn(sgl, alloc_size); sgl = next; } -- cgit v1.2.3 From ea5d05b34aca25c066e0699512d0ffbd8ee6ac3e Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Wed, 29 Oct 2014 14:50:44 -0700 Subject: lib/bitmap.c: fix undefined shift in __bitmap_shift_{left|right}() If __bitmap_shift_left() or __bitmap_shift_right() are asked to shift by a multiple of BITS_PER_LONG, they will try to shift a long value by BITS_PER_LONG bits which is undefined. Change the functions to avoid the undefined shift. Coverity id: 1192175 Coverity id: 1192174 Signed-off-by: Jan Kara Cc: Rasmus Villemoes Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- lib/bitmap.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/bitmap.c b/lib/bitmap.c index cd250a2e14cb..b499ab6ada29 100644 --- a/lib/bitmap.c +++ b/lib/bitmap.c @@ -131,7 +131,9 @@ void __bitmap_shift_right(unsigned long *dst, lower = src[off + k]; if (left && off + k == lim - 1) lower &= mask; - dst[k] = upper << (BITS_PER_LONG - rem) | lower >> rem; + dst[k] = lower >> rem; + if (rem) + dst[k] |= upper << (BITS_PER_LONG - rem); if (left && k == lim - 1) dst[k] &= mask; } @@ -172,7 +174,9 @@ void __bitmap_shift_left(unsigned long *dst, upper = src[k]; if (left && k == lim - 1) upper &= (1UL << left) - 1; - dst[k + off] = lower >> (BITS_PER_LONG - rem) | upper << rem; + dst[k + off] = upper << rem; + if (rem) + dst[k + off] |= lower >> (BITS_PER_LONG - rem); if (left && k + off == lim - 1) dst[k + off] &= (1UL << left) - 1; } -- cgit v1.2.3