From 226d44acf6dfe71c9df5804b82364e93cf908b53 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Fri, 8 Apr 2022 11:45:53 +0200 Subject: lib/strn*,objtool: Enforce user_access_begin() rules Apparently GCC can fail to inline a 'static inline' single caller function: lib/strnlen_user.o: warning: objtool: strnlen_user()+0x33: call to do_strnlen_user() with UACCESS enabled lib/strncpy_from_user.o: warning: objtool: strncpy_from_user()+0x33: call to do_strncpy_from_user() with UACCESS enabled Reported-by: Thomas Gleixner Signed-off-by: Peter Zijlstra (Intel) Acked-by: Josh Poimboeuf Link: https://lore.kernel.org/r/20220408094718.262932488@infradead.org --- lib/strncpy_from_user.c | 2 +- lib/strnlen_user.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) (limited to 'lib') diff --git a/lib/strncpy_from_user.c b/lib/strncpy_from_user.c index 08fc72d3ed16..6432b8c3e431 100644 --- a/lib/strncpy_from_user.c +++ b/lib/strncpy_from_user.c @@ -25,7 +25,7 @@ * 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, +static __always_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; diff --git a/lib/strnlen_user.c b/lib/strnlen_user.c index bffa0ebf9f8b..feeb935a2299 100644 --- a/lib/strnlen_user.c +++ b/lib/strnlen_user.c @@ -20,7 +20,7 @@ * if it fits in a aligned 'long'. The caller needs to check * the return value against "> max". */ -static inline long do_strnlen_user(const char __user *src, unsigned long count, unsigned long max) +static __always_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; unsigned long align, res = 0; -- cgit v1.2.3 From e5be15767e7e284351853cbaba80cde8620341fb Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Mon, 25 Apr 2022 08:07:48 -0400 Subject: hex2bin: make the function hex_to_bin constant-time The function hex2bin is used to load cryptographic keys into device mapper targets dm-crypt and dm-integrity. It should take constant time independent on the processed data, so that concurrently running unprivileged code can't infer any information about the keys via microarchitectural convert channels. This patch changes the function hex_to_bin so that it contains no branches and no memory accesses. Note that this shouldn't cause performance degradation because the size of the new function is the same as the size of the old function (on x86-64) - and the new function causes no branch misprediction penalties. I compile-tested this function with gcc on aarch64 alpha arm hppa hppa64 i386 ia64 m68k mips32 mips64 powerpc powerpc64 riscv sh4 s390x sparc32 sparc64 x86_64 and with clang on aarch64 arm hexagon i386 mips32 mips64 powerpc powerpc64 s390x sparc32 sparc64 x86_64 to verify that there are no branches in the generated code. Signed-off-by: Mikulas Patocka Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- lib/hexdump.c | 32 +++++++++++++++++++++++++------- 1 file changed, 25 insertions(+), 7 deletions(-) (limited to 'lib') diff --git a/lib/hexdump.c b/lib/hexdump.c index 9301578f98e8..369420ce553a 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -22,15 +22,33 @@ EXPORT_SYMBOL(hex_asc_upper); * * hex_to_bin() converts one hex digit to its actual value or -1 in case of bad * input. + * + * This function is used to load cryptographic keys, so it is coded in such a + * way that there are no conditions or memory accesses that depend on data. + * + * Explanation of the logic: + * (ch - '9' - 1) is negative if ch <= '9' + * ('0' - 1 - ch) is negative if ch >= '0' + * we "and" these two values, so the result is negative if ch is in the range + * '0' ... '9' + * we are only interested in the sign, so we do a shift ">> 8"; note that right + * shift of a negative value is implementation-defined, so we cast the + * value to (unsigned) before the shift --- we have 0xffffff if ch is in + * the range '0' ... '9', 0 otherwise + * we "and" this value with (ch - '0' + 1) --- we have a value 1 ... 10 if ch is + * in the range '0' ... '9', 0 otherwise + * we add this value to -1 --- we have a value 0 ... 9 if ch is in the range '0' + * ... '9', -1 otherwise + * the next line is similar to the previous one, but we need to decode both + * uppercase and lowercase letters, so we use (ch & 0xdf), which converts + * lowercase to uppercase */ -int hex_to_bin(char ch) +int hex_to_bin(unsigned char ch) { - if ((ch >= '0') && (ch <= '9')) - return ch - '0'; - ch = tolower(ch); - if ((ch >= 'a') && (ch <= 'f')) - return ch - 'a' + 10; - return -1; + unsigned char cu = ch & 0xdf; + return -1 + + ((ch - '0' + 1) & (unsigned)((ch - '9' - 1) & ('0' - 1 - ch)) >> 8) + + ((cu - 'A' + 11) & (unsigned)((cu - 'F' - 1) & ('A' - 1 - cu)) >> 8); } EXPORT_SYMBOL(hex_to_bin); -- cgit v1.2.3 From e4d8a29997731b3bb14059024b24df9f784288d0 Mon Sep 17 00:00:00 2001 From: Mikulas Patocka Date: Wed, 27 Apr 2022 11:26:40 -0400 Subject: hex2bin: fix access beyond string end If we pass too short string to "hex2bin" (and the string size without the terminating NUL character is even), "hex2bin" reads one byte after the terminating NUL character. This patch fixes it. Note that hex_to_bin returns -1 on error and hex2bin return -EINVAL on error - so we can't just return the variable "hi" or "lo" on error. This inconsistency may be fixed in the next merge window, but for the purpose of fixing this bug, we just preserve the existing behavior and return -1 and -EINVAL. Signed-off-by: Mikulas Patocka Reviewed-by: Andy Shevchenko Fixes: b78049831ffe ("lib: add error checking to hex2bin") Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds --- lib/hexdump.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-) (limited to 'lib') diff --git a/lib/hexdump.c b/lib/hexdump.c index 369420ce553a..06833d404398 100644 --- a/lib/hexdump.c +++ b/lib/hexdump.c @@ -63,10 +63,13 @@ EXPORT_SYMBOL(hex_to_bin); int hex2bin(u8 *dst, const char *src, size_t count) { while (count--) { - int hi = hex_to_bin(*src++); - int lo = hex_to_bin(*src++); + int hi, lo; - if ((hi < 0) || (lo < 0)) + hi = hex_to_bin(*src++); + if (unlikely(hi < 0)) + return -EINVAL; + lo = hex_to_bin(*src++); + if (unlikely(lo < 0)) return -EINVAL; *dst++ = (hi << 4) | lo; -- cgit v1.2.3 From ee1444b5e1df4155b591d0d9b1e72853a99ea861 Mon Sep 17 00:00:00 2001 From: Jesse Brandeburg Date: Fri, 6 May 2022 18:10:38 -0700 Subject: dim: initialize all struct fields MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The W=2 build pointed out that the code wasn't initializing all the variables in the dim_cq_moder declarations with the struct initializers. The net change here is zero since these structs were already static const globals and were initialized with zeros by the compiler, but removing compiler warnings has value in and of itself. lib/dim/net_dim.c: At top level: lib/dim/net_dim.c:54:9: warning: missing initializer for field ‘comps’ of ‘const struct dim_cq_moder’ [-Wmissing-field-initializers] 54 | NET_DIM_RX_EQE_PROFILES, | ^~~~~~~~~~~~~~~~~~~~~~~ In file included from lib/dim/net_dim.c:6: ./include/linux/dim.h:45:13: note: ‘comps’ declared here 45 | u16 comps; | ^~~~~ and repeats for the tx struct, and once you fix the comps entry then the cq_period_mode field needs the same treatment. Use the commonly accepted style to indicate to the compiler that we know what we're doing, and add a comma at the end of each struct initializer to clean up the issue, and use explicit initializers for the fields we are initializing which makes the compiler happy. While here and fixing these lines, clean up the code slightly with a fix for the super long lines by removing the word "_MODERATION" from a couple defines only used in this file. Fixes: f8be17b81d44 ("lib/dim: Fix -Wunused-const-variable warnings") Signed-off-by: Jesse Brandeburg Link: https://lore.kernel.org/r/20220507011038.14568-1-jesse.brandeburg@intel.com Signed-off-by: Jakub Kicinski --- lib/dim/net_dim.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) (limited to 'lib') diff --git a/lib/dim/net_dim.c b/lib/dim/net_dim.c index 06811d866775..53f6b9c6e936 100644 --- a/lib/dim/net_dim.c +++ b/lib/dim/net_dim.c @@ -12,41 +12,41 @@ * Each profile size must be of NET_DIM_PARAMS_NUM_PROFILES */ #define NET_DIM_PARAMS_NUM_PROFILES 5 -#define NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE 256 -#define NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE 128 +#define NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE 256 +#define NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE 128 #define NET_DIM_DEF_PROFILE_CQE 1 #define NET_DIM_DEF_PROFILE_EQE 1 #define NET_DIM_RX_EQE_PROFILES { \ - {1, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {8, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {64, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {128, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {256, NET_DIM_DEFAULT_RX_CQ_MODERATION_PKTS_FROM_EQE}, \ + {.usec = 1, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 8, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 64, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 128, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 256, .pkts = NET_DIM_DEFAULT_RX_CQ_PKTS_FROM_EQE,} \ } #define NET_DIM_RX_CQE_PROFILES { \ - {2, 256}, \ - {8, 128}, \ - {16, 64}, \ - {32, 64}, \ - {64, 64} \ + {.usec = 2, .pkts = 256,}, \ + {.usec = 8, .pkts = 128,}, \ + {.usec = 16, .pkts = 64,}, \ + {.usec = 32, .pkts = 64,}, \ + {.usec = 64, .pkts = 64,} \ } #define NET_DIM_TX_EQE_PROFILES { \ - {1, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {8, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {32, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {64, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE}, \ - {128, NET_DIM_DEFAULT_TX_CQ_MODERATION_PKTS_FROM_EQE} \ + {.usec = 1, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 8, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 32, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 64, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,}, \ + {.usec = 128, .pkts = NET_DIM_DEFAULT_TX_CQ_PKTS_FROM_EQE,} \ } #define NET_DIM_TX_CQE_PROFILES { \ - {5, 128}, \ - {8, 64}, \ - {16, 32}, \ - {32, 32}, \ - {64, 32} \ + {.usec = 5, .pkts = 128,}, \ + {.usec = 8, .pkts = 64,}, \ + {.usec = 16, .pkts = 32,}, \ + {.usec = 32, .pkts = 32,}, \ + {.usec = 64, .pkts = 32,} \ } static const struct dim_cq_moder -- cgit v1.2.3