diff options
Diffstat (limited to 'sys-apps/systemd/files/242-rdrand-ryzen.patch')
| -rw-r--r-- | sys-apps/systemd/files/242-rdrand-ryzen.patch | 353 |
1 files changed, 353 insertions, 0 deletions
diff --git a/sys-apps/systemd/files/242-rdrand-ryzen.patch b/sys-apps/systemd/files/242-rdrand-ryzen.patch new file mode 100644 index 000000000000..ec690c1b3f6c --- /dev/null +++ b/sys-apps/systemd/files/242-rdrand-ryzen.patch @@ -0,0 +1,353 @@ +From d351699739471734666230ae3c6f9ba56ce5ce45 Mon Sep 17 00:00:00 2001 +From: Lennart Poettering <lennart@poettering.net> +Date: Tue, 7 May 2019 16:18:13 -0400 +Subject: [PATCH 1/6] =?UTF-8?q?random-util:=20rename=20RANDOM=5FDONT=5FDRA?= + =?UTF-8?q?IN=20=E2=86=92=20RANDOM=5FMAY=5FFAIL?= +MIME-Version: 1.0 +Content-Type: text/plain; charset=UTF-8 +Content-Transfer-Encoding: 8bit + +The old flag name was a bit of a misnomer, as /dev/urandom cannot be +"drained". Once it's initialized it's initialized and then is good +forever. (Only /dev/random has a concept of 'draining', but we never use +that, as it's an obsolete interface). + +The flag is still useful though, since it allows us to suppress accesses +to the random pool while it is not initialized, as that trips up the +kernel and it logs about any such attempts, which we really don't want. + +(cherry picked from commit 1a0ffa1e737e65312abac63dcf4b44e1ac0e1642) +--- + src/basic/random-util.c | 36 +++++++++++++++++++----------------- + src/basic/random-util.h | 4 ++-- + 2 files changed, 21 insertions(+), 19 deletions(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index ca25fd2420..de29e07549 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -71,21 +71,22 @@ int genuine_random_bytes(void *p, size_t n, RandomFlags flags) { + bool got_some = false; + int r; + +- /* Gathers some randomness from the kernel (or the CPU if the RANDOM_ALLOW_RDRAND flag is set). This call won't +- * block, unless the RANDOM_BLOCK flag is set. If RANDOM_DONT_DRAIN is set, an error is returned if the random +- * pool is not initialized. Otherwise it will always return some data from the kernel, regardless of whether +- * the random pool is fully initialized or not. */ ++ /* Gathers some randomness from the kernel (or the CPU if the RANDOM_ALLOW_RDRAND flag is set). This ++ * call won't block, unless the RANDOM_BLOCK flag is set. If RANDOM_MAY_FAIL is set, an error is ++ * returned if the random pool is not initialized. Otherwise it will always return some data from the ++ * kernel, regardless of whether the random pool is fully initialized or not. */ + + if (n == 0) + return 0; + + if (FLAGS_SET(flags, RANDOM_ALLOW_RDRAND)) +- /* Try x86-64' RDRAND intrinsic if we have it. We only use it if high quality randomness is not +- * required, as we don't trust it (who does?). Note that we only do a single iteration of RDRAND here, +- * even though the Intel docs suggest calling this in a tight loop of 10 invocations or so. That's +- * because we don't really care about the quality here. We generally prefer using RDRAND if the caller +- * allows us too, since this way we won't drain the kernel randomness pool if we don't need it, as the +- * pool's entropy is scarce. */ ++ /* Try x86-64' RDRAND intrinsic if we have it. We only use it if high quality randomness is ++ * not required, as we don't trust it (who does?). Note that we only do a single iteration of ++ * RDRAND here, even though the Intel docs suggest calling this in a tight loop of 10 ++ * invocations or so. That's because we don't really care about the quality here. We ++ * generally prefer using RDRAND if the caller allows us to, since this way we won't upset ++ * the kernel's random subsystem by accessing it before the pool is initialized (after all it ++ * will kmsg log about every attempt to do so)..*/ + for (;;) { + unsigned long u; + size_t m; +@@ -153,12 +154,13 @@ int genuine_random_bytes(void *p, size_t n, RandomFlags flags) { + break; + + } else if (errno == EAGAIN) { +- /* The kernel has no entropy whatsoever. Let's remember to use the syscall the next +- * time again though. ++ /* The kernel has no entropy whatsoever. Let's remember to use the syscall ++ * the next time again though. + * +- * If RANDOM_DONT_DRAIN is set, return an error so that random_bytes() can produce some +- * pseudo-random bytes instead. Otherwise, fall back to /dev/urandom, which we know is empty, +- * but the kernel will produce some bytes for us on a best-effort basis. */ ++ * If RANDOM_MAY_FAIL is set, return an error so that random_bytes() can ++ * produce some pseudo-random bytes instead. Otherwise, fall back to ++ * /dev/urandom, which we know is empty, but the kernel will produce some ++ * bytes for us on a best-effort basis. */ + have_syscall = true; + + if (got_some && FLAGS_SET(flags, RANDOM_EXTEND_WITH_PSEUDO)) { +@@ -167,7 +169,7 @@ int genuine_random_bytes(void *p, size_t n, RandomFlags flags) { + return 0; + } + +- if (FLAGS_SET(flags, RANDOM_DONT_DRAIN)) ++ if (FLAGS_SET(flags, RANDOM_MAY_FAIL)) + return -ENODATA; + + /* Use /dev/urandom instead */ +@@ -250,7 +252,7 @@ void pseudo_random_bytes(void *p, size_t n) { + + void random_bytes(void *p, size_t n) { + +- if (genuine_random_bytes(p, n, RANDOM_EXTEND_WITH_PSEUDO|RANDOM_DONT_DRAIN|RANDOM_ALLOW_RDRAND) >= 0) ++ if (genuine_random_bytes(p, n, RANDOM_EXTEND_WITH_PSEUDO|RANDOM_MAY_FAIL|RANDOM_ALLOW_RDRAND) >= 0) + return; + + /* If for some reason some user made /dev/urandom unavailable to us, or the kernel has no entropy, use a PRNG instead. */ +diff --git a/src/basic/random-util.h b/src/basic/random-util.h +index 3e8c288d3d..148b6c7813 100644 +--- a/src/basic/random-util.h ++++ b/src/basic/random-util.h +@@ -8,11 +8,11 @@ + typedef enum RandomFlags { + RANDOM_EXTEND_WITH_PSEUDO = 1 << 0, /* If we can't get enough genuine randomness, but some, fill up the rest with pseudo-randomness */ + RANDOM_BLOCK = 1 << 1, /* Rather block than return crap randomness (only if the kernel supports that) */ +- RANDOM_DONT_DRAIN = 1 << 2, /* If we can't get any randomness at all, return early with -EAGAIN */ ++ RANDOM_MAY_FAIL = 1 << 2, /* If we can't get any randomness at all, return early with -ENODATA */ + RANDOM_ALLOW_RDRAND = 1 << 3, /* Allow usage of the CPU RNG */ + } RandomFlags; + +-int genuine_random_bytes(void *p, size_t n, RandomFlags flags); /* returns "genuine" randomness, optionally filled upwith pseudo random, if not enough is available */ ++int genuine_random_bytes(void *p, size_t n, RandomFlags flags); /* returns "genuine" randomness, optionally filled up with pseudo random, if not enough is available */ + void pseudo_random_bytes(void *p, size_t n); /* returns only pseudo-randommess (but possibly seeded from something better) */ + void random_bytes(void *p, size_t n); /* returns genuine randomness if cheaply available, and pseudo randomness if not. */ + +-- +2.22.0 + + +From 1f492b9ecc31aa3782f9ce82058d8fb72a5c323f Mon Sep 17 00:00:00 2001 +From: Lennart Poettering <lennart@poettering.net> +Date: Tue, 7 May 2019 16:21:44 -0400 +Subject: [PATCH 2/6] random-util: use gcc's bit_RDRND definition if it exists + +(cherry picked from commit cc28145d51f62711fdc4b4c229aecd5778806419) +--- + src/basic/random-util.c | 7 ++++++- + 1 file changed, 6 insertions(+), 1 deletion(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index de29e07549..205d5501e5 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -45,7 +45,12 @@ int rdrand(unsigned long *ret) { + return -EOPNOTSUPP; + } + +- have_rdrand = !!(ecx & (1U << 30)); ++/* Compat with old gcc where bit_RDRND didn't exist yet */ ++#ifndef bit_RDRND ++#define bit_RDRND (1U << 30) ++#endif ++ ++ have_rdrand = !!(ecx & bit_RDRND); + } + + if (have_rdrand == 0) +-- +2.22.0 + + +From 6460c540e6183dd19de89b7f0672b3b47c4d41cc Mon Sep 17 00:00:00 2001 +From: Lennart Poettering <lennart@poettering.net> +Date: Tue, 7 May 2019 17:26:55 -0400 +Subject: [PATCH 3/6] random-util: hash AT_RANDOM getauxval() value before + using it + +Let's be a bit paranoid and hash the 16 bytes we get from getauxval() +before using them. AFter all they might be used by other stuff too (in +particular ASLR), and we probably shouldn't end up leaking that seed +though our crappy pseudo-random numbers. + +(cherry picked from commit 80eb560a5bd7439103036867d5e09a5e0393e5d3) +--- + src/basic/random-util.c | 18 ++++++++++++------ + 1 file changed, 12 insertions(+), 6 deletions(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index 205d5501e5..40f1928936 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -28,6 +28,7 @@ + #include "io-util.h" + #include "missing.h" + #include "random-util.h" ++#include "siphash24.h" + #include "time-util.h" + + int rdrand(unsigned long *ret) { +@@ -203,14 +204,19 @@ void initialize_srand(void) { + return; + + #if HAVE_SYS_AUXV_H +- /* The kernel provides us with 16 bytes of entropy in auxv, so let's +- * try to make use of that to seed the pseudo-random generator. It's +- * better than nothing... */ ++ /* The kernel provides us with 16 bytes of entropy in auxv, so let's try to make use of that to seed ++ * the pseudo-random generator. It's better than nothing... But let's first hash it to make it harder ++ * to recover the original value by watching any pseudo-random bits we generate. After all the ++ * AT_RANDOM data might be used by other stuff too (in particular: ASLR), and we probably shouldn't ++ * leak the seed for that. */ + +- auxv = (const void*) getauxval(AT_RANDOM); ++ auxv = ULONG_TO_PTR(getauxval(AT_RANDOM)); + if (auxv) { +- assert_cc(sizeof(x) <= 16); +- memcpy(&x, auxv, sizeof(x)); ++ static const uint8_t auxval_hash_key[16] = { ++ 0x92, 0x6e, 0xfe, 0x1b, 0xcf, 0x00, 0x52, 0x9c, 0xcc, 0x42, 0xcf, 0xdc, 0x94, 0x1f, 0x81, 0x0f ++ }; ++ ++ x = (unsigned) siphash24(auxv, 16, auxval_hash_key); + } else + #endif + x = 0; +-- +2.22.0 + + +From 17d52f6320b45d1728af6007b4df4aaccc6fdaf4 Mon Sep 17 00:00:00 2001 +From: Lennart Poettering <lennart@poettering.net> +Date: Tue, 7 May 2019 18:51:26 -0400 +Subject: [PATCH 4/6] random-util: rename "err" to "success" + +After all rdrand returns 1 on success, and 0 on failure, hence let's +name this accordingly. + +(cherry picked from commit 328f850e36e86d14ab06d11fa8f2397e9575a7f9) +--- + src/basic/random-util.c | 8 ++++---- + 1 file changed, 4 insertions(+), 4 deletions(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index 40f1928936..7c64857592 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -35,7 +35,7 @@ int rdrand(unsigned long *ret) { + + #if defined(__i386__) || defined(__x86_64__) + static int have_rdrand = -1; +- unsigned char err; ++ uint8_t success; + + if (have_rdrand < 0) { + uint32_t eax, ebx, ecx, edx; +@@ -60,9 +60,9 @@ int rdrand(unsigned long *ret) { + asm volatile("rdrand %0;" + "setc %1" + : "=r" (*ret), +- "=qm" (err)); +- msan_unpoison(&err, sizeof(err)); +- if (!err) ++ "=qm" (success)); ++ msan_unpoison(&success, sizeof(sucess)); ++ if (!success) + return -EAGAIN; + + return 0; +-- +2.22.0 + + +From a6c72245ba5ba688cd6544650b9c6e313b39b53e Mon Sep 17 00:00:00 2001 +From: Evgeny Vereshchagin <evvers@ya.ru> +Date: Wed, 8 May 2019 15:50:53 +0200 +Subject: [PATCH 5/6] util-lib: fix a typo in rdrand + +Otherwise, the fuzzers will fail to compile with MSan: +``` +../../src/systemd/src/basic/random-util.c:64:40: error: use of undeclared identifier 'sucess'; did you mean 'success'? + msan_unpoison(&success, sizeof(sucess)); + ^~~~~~ + success +../../src/systemd/src/basic/alloc-util.h:169:50: note: expanded from macro 'msan_unpoison' + ^ +../../src/systemd/src/basic/random-util.c:38:17: note: 'success' declared here + uint8_t success; + ^ +1 error generated. +[80/545] Compiling C object 'src/basic/a6ba3eb@@basic@sta/process-util.c.o'. +ninja: build stopped: subcommand failed. +Fuzzers build failed +``` + +(cherry picked from commit 7f2cdceaed4d37c4e601e531c7d863fca1bd1460) +--- + src/basic/random-util.c | 2 +- + 1 file changed, 1 insertion(+), 1 deletion(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index 7c64857592..b8bbf2d418 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -61,7 +61,7 @@ int rdrand(unsigned long *ret) { + "setc %1" + : "=r" (*ret), + "=qm" (success)); +- msan_unpoison(&success, sizeof(sucess)); ++ msan_unpoison(&success, sizeof(success)); + if (!success) + return -EAGAIN; + +-- +2.22.0 + + +From 47eec0ae61c887cb8cc05ce8d49b8d151bc4ef25 Mon Sep 17 00:00:00 2001 +From: Lennart Poettering <lennart@poettering.net> +Date: Fri, 10 May 2019 15:16:16 -0400 +Subject: [PATCH 6/6] random-util: eat up bad RDRAND values seen on AMD CPUs + +An ugly, ugly work-around for #11810. And no, we shouldn't have to do +this. This is something for AMD, the firmware or the kernel to +fix/work-around, not us. But nonetheless, this should do it for now. + +Fixes: #11810 +(cherry picked from commit 1c53d4a070edbec8ad2d384ba0014d0eb6bae077) +--- + src/basic/random-util.c | 15 ++++++++++++++- + 1 file changed, 14 insertions(+), 1 deletion(-) + +diff --git a/src/basic/random-util.c b/src/basic/random-util.c +index b8bbf2d418..0561f0cb22 100644 +--- a/src/basic/random-util.c ++++ b/src/basic/random-util.c +@@ -35,6 +35,7 @@ int rdrand(unsigned long *ret) { + + #if defined(__i386__) || defined(__x86_64__) + static int have_rdrand = -1; ++ unsigned long v; + uint8_t success; + + if (have_rdrand < 0) { +@@ -59,12 +60,24 @@ int rdrand(unsigned long *ret) { + + asm volatile("rdrand %0;" + "setc %1" +- : "=r" (*ret), ++ : "=r" (v), + "=qm" (success)); + msan_unpoison(&success, sizeof(success)); + if (!success) + return -EAGAIN; + ++ /* Apparently on some AMD CPUs RDRAND will sometimes (after a suspend/resume cycle?) report success ++ * via the carry flag but nonetheless return the same fixed value -1 in all cases. This appears to be ++ * a bad bug in the CPU or firmware. Let's deal with that and work-around this by explicitly checking ++ * for this special value (and also 0, just to be sure) and filtering it out. This is a work-around ++ * only however and something AMD really should fix properly. The Linux kernel should probably work ++ * around this issue by turning off RDRAND altogether on those CPUs. See: ++ * https://github.com/systemd/systemd/issues/11810 */ ++ if (v == 0 || v == ULONG_MAX) ++ return log_debug_errno(SYNTHETIC_ERRNO(EUCLEAN), ++ "RDRAND returned suspicious value %lx, assuming bad hardware RNG, not using value.", v); ++ ++ *ret = v; + return 0; + #else + return -EOPNOTSUPP; +-- +2.22.0 + |