From 034dd340b08be1f2f0477ad16131d609f9dbd53c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sun, 30 Aug 2026 09:22:00 -0700 Subject: Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace Pull tracing fixes from Steven Rostedt: - Fix error output of boot instance creation failure Currently if a boot instance creation fails, instead of printing out the name of the instance that failed, it prints "(null)". That is because it prints "cur_str" that had already been processed by strsep(). Print the saved name instead. While at it, print the error code of the failure. - Fix use-after-free for same named historgrams Histograms can be named so that they can be used in multiple events. But if the named histogram has a variable attached, the second event that uses the named histogram which duplicates it and needs to free the original after duplication leaves the old variable in place and still visible. If another histogram uses than variable, it will use the stale one which will try to reference the freed duplicate histogram and crash the kernel. Free the duplicate variables along with the duplicated histogram data. - Check return value of kthread_run() in event self test The events self tests uses a kthread for testing but does not check if it succeeded in creating a kthread. If the kthread creation were to fail, the code will still try to call kthread_stop() on the error returned. - Fix race between reading trace_pipe and updating subbuffer size If a user is reading the trace_pipe file at the same time they update the ring buffer sub-buffer size, can cause the trace_pipe read to read stale data. Add trace_access_lock() around updating the ring buffer sub-buffer size. - Fix eventfs_inode on failure path in creation of the events directory In the creation of the "events" directory, if after allocating the eventfs_inode a failure is detected, it calls cleanup_ei() which calls free_ei(). The free_ei() will test if eventfs_inode being freed has no children. It is a bug if it does. But on the failure case of the creation of the "events" directory, the children lists have not yet been initialized and the free will trigger a warning because list_empty() on an uninitialized list returns false. Move the initialization into init_ei() where it makes more sense and makes sure that a created eventfs_inode has its lists initialized upon creation. - Check return value of kthread_run() in ftrace direct sample code The sample code that shows how to use the ftrace direct calls does not test the return of kthread_run() to see if it succeeds. Return a failure if the kthread_run() doesn't succeed. - Clear user events state on fork in case of alloc failure On fork, the child gets a pointer to the parent's user events state. It makes a copy of it then updates the child's pointer to it. But if the allocation fails, the duplication function leaves the child with a pointer to its parent's descriptor. When the child cleans up its data, it will free the parent's descriptor while the parent is still using it. In the duplication function, set the child's user_event_mm to NULL before testing if the allocation succeeded, and when it exits it will not free the parent's descriptor. - Fix retry exhaustion in simple ring buffer reader swap simple_ring_buffer_swap_reader_page() starts with retry set to 8 and post-decrements it only after a failed link replacement. On the final attempt, a successful replacement leaves retry at zero, while a failed replacement leaves it at -1. But the check for success expects the retry value to be non-zero and exits with an error on zero. This is the opposite result. Fix it. - Fail nicely when the remote swap_reader_page() returns an error Currently, if the swap_reader_page() of a remote buffer fails, it triggers a WARN_ON_ONCE() and continues normally. Instead, have it exit with an error and a pr_warn() print instead of a full WARNING. * tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace: ring-buffer: Stop remote reader update when page swap fails tracing: Fix retry exhaustion in simple ring buffer reader swap tracing/user_events: Clear copied tracing state before fork duplication samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify eventfs: Initialize ei->children and ei->list in init_ei() tracing: Fix use-after-free in trace_pipe read on sub-buffer order change tracing: Fix crash passing ERR_PTR to kthread_stop() tracing: Fix use-after-free with same-name named triggers tracing: Fix logged instance name on creation failure --- lib/crypto/mpi/mpicoder.c | 417 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 417 insertions(+) create mode 100644 lib/crypto/mpi/mpicoder.c (limited to 'lib/crypto/mpi/mpicoder.c') diff --git a/lib/crypto/mpi/mpicoder.c b/lib/crypto/mpi/mpicoder.c new file mode 100644 index 000000000..9359a58c2 --- /dev/null +++ b/lib/crypto/mpi/mpicoder.c @@ -0,0 +1,417 @@ +/* mpicoder.c - Coder for the external representation of MPIs + * Copyright (C) 1998, 1999 Free Software Foundation, Inc. + * + * This file is part of GnuPG. + * + * GnuPG is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * GnuPG is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA + */ + +#include +#include +#include +#include +#include +#include +#include "mpi-internal.h" + +#define MAX_EXTERN_MPI_BITS 16384 + +/** + * mpi_read_raw_data - Read a raw byte stream as a positive integer + * @xbuffer: The data to read + * @nbytes: The amount of data to read + */ +MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) +{ + const uint8_t *buffer = xbuffer; + int i, j; + unsigned nbits, nlimbs; + mpi_limb_t a; + MPI val = NULL; + + while (nbytes > 0 && buffer[0] == 0) { + buffer++; + nbytes--; + } + + nbits = nbytes * 8; + if (nbits > MAX_EXTERN_MPI_BITS) { + pr_info("MPI: mpi too large (%u bits)\n", nbits); + return NULL; + } + if (nbytes > 0) + nbits -= count_leading_zeros(buffer[0]) - (BITS_PER_LONG - 8); + + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); + val = mpi_alloc(nlimbs); + if (!val) + return NULL; + val->nbits = nbits; + val->sign = 0; + val->nlimbs = nlimbs; + + if (nbytes > 0) { + i = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; + i %= BYTES_PER_MPI_LIMB; + for (j = nlimbs; j > 0; j--) { + a = 0; + for (; i < BYTES_PER_MPI_LIMB; i++) { + a <<= 8; + a |= *buffer++; + } + i = 0; + val->d[j - 1] = a; + } + } + return val; +} +EXPORT_SYMBOL_GPL(mpi_read_raw_data); + +MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) +{ + const uint8_t *buffer = xbuffer; + unsigned int nbits, nbytes; + MPI val; + + if (*ret_nread < 2) + return ERR_PTR(-EINVAL); + nbits = buffer[0] << 8 | buffer[1]; + + if (nbits > MAX_EXTERN_MPI_BITS) { + pr_info("MPI: mpi too large (%u bits)\n", nbits); + return ERR_PTR(-EINVAL); + } + + nbytes = DIV_ROUND_UP(nbits, 8); + if (nbytes + 2 > *ret_nread) { + pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", + nbytes, *ret_nread); + return ERR_PTR(-EINVAL); + } + + val = mpi_read_raw_data(buffer + 2, nbytes); + if (!val) + return ERR_PTR(-ENOMEM); + + *ret_nread = nbytes + 2; + return val; +} +EXPORT_SYMBOL_GPL(mpi_read_from_buffer); + +static int count_lzeros(MPI a) +{ + mpi_limb_t alimb; + int i, lzeros = 0; + + for (i = a->nlimbs - 1; i >= 0; i--) { + alimb = a->d[i]; + if (alimb == 0) { + lzeros += sizeof(mpi_limb_t); + } else { + lzeros += count_leading_zeros(alimb) / 8; + break; + } + } + return lzeros; +} + +/** + * mpi_read_buffer() - read MPI to a buffer provided by user (msb first) + * + * @a: a multi precision integer + * @buf: buffer to which the output will be written to. Needs to be at + * least mpi_get_size(a) long. + * @buf_len: size of the buf. + * @nbytes: receives the actual length of the data written on success and + * the data to-be-written on -EOVERFLOW in case buf_len was too + * small. + * @sign: if not NULL, it will be set to the sign of a. + * + * Return: 0 on success or error code in case of error + */ +int mpi_read_buffer(MPI a, uint8_t *buf, unsigned buf_len, unsigned *nbytes, + int *sign) +{ + uint8_t *p; +#if BYTES_PER_MPI_LIMB == 4 + __be32 alimb; +#elif BYTES_PER_MPI_LIMB == 8 + __be64 alimb; +#else +#error please implement for this limb size. +#endif + unsigned int n = mpi_get_size(a); + int i, lzeros; + + if (!buf || !nbytes) + return -EINVAL; + + if (sign) + *sign = a->sign; + + lzeros = count_lzeros(a); + + if (buf_len < n - lzeros) { + *nbytes = n - lzeros; + return -EOVERFLOW; + } + + p = buf; + *nbytes = n - lzeros; + + for (i = a->nlimbs - 1 - lzeros / BYTES_PER_MPI_LIMB, + lzeros %= BYTES_PER_MPI_LIMB; + i >= 0; i--) { +#if BYTES_PER_MPI_LIMB == 4 + alimb = cpu_to_be32(a->d[i]); +#elif BYTES_PER_MPI_LIMB == 8 + alimb = cpu_to_be64(a->d[i]); +#else +#error please implement for this limb size. +#endif + memcpy(p, (u8 *)&alimb + lzeros, BYTES_PER_MPI_LIMB - lzeros); + p += BYTES_PER_MPI_LIMB - lzeros; + lzeros = 0; + } + return 0; +} +EXPORT_SYMBOL_GPL(mpi_read_buffer); + +/* + * mpi_get_buffer() - Returns an allocated buffer with the MPI (msb first). + * Caller must free the return string. + * This function does return a 0 byte buffer with nbytes set to zero if the + * value of A is zero. + * + * @a: a multi precision integer. + * @nbytes: receives the length of this buffer. + * @sign: if not NULL, it will be set to the sign of the a. + * + * Return: Pointer to MPI buffer or NULL on error + */ +void *mpi_get_buffer(MPI a, unsigned *nbytes, int *sign) +{ + uint8_t *buf; + unsigned int n; + int ret; + + if (!nbytes) + return NULL; + + n = mpi_get_size(a); + + if (!n) + n++; + + buf = kmalloc(n, GFP_KERNEL); + + if (!buf) + return NULL; + + ret = mpi_read_buffer(a, buf, n, nbytes, sign); + + if (ret) { + kfree(buf); + return NULL; + } + return buf; +} +EXPORT_SYMBOL_GPL(mpi_get_buffer); + +/** + * mpi_write_to_sgl() - Funnction exports MPI to an sgl (msb first) + * + * This function works in the same way as the mpi_read_buffer, but it + * takes an sgl instead of u8 * buf. + * + * @a: a multi precision integer + * @sgl: scatterlist to write to. Needs to be at least + * mpi_get_size(a) long. + * @nbytes: the number of bytes to write. Leading bytes will be + * filled with zero. + * @sign: if not NULL, it will be set to the sign of a. + * + * Return: 0 on success or error code in case of error + */ +int mpi_write_to_sgl(MPI a, struct scatterlist *sgl, unsigned nbytes, + int *sign) +{ + u8 *p, *p2; +#if BYTES_PER_MPI_LIMB == 4 + __be32 alimb; +#elif BYTES_PER_MPI_LIMB == 8 + __be64 alimb; +#else +#error please implement for this limb size. +#endif + unsigned int n = mpi_get_size(a); + struct sg_mapping_iter miter; + int i, x, buf_len; + int nents; + + if (sign) + *sign = a->sign; + + if (nbytes < n) + return -EOVERFLOW; + + nents = sg_nents_for_len(sgl, nbytes); + if (nents < 0) + return -EINVAL; + + sg_miter_start(&miter, sgl, nents, SG_MITER_ATOMIC | SG_MITER_TO_SG); + sg_miter_next(&miter); + buf_len = miter.length; + p2 = miter.addr; + + while (nbytes > n) { + i = min_t(unsigned, nbytes - n, buf_len); + memset(p2, 0, i); + p2 += i; + nbytes -= i; + + buf_len -= i; + if (!buf_len) { + sg_miter_next(&miter); + buf_len = miter.length; + p2 = miter.addr; + } + } + + for (i = a->nlimbs - 1; i >= 0; i--) { +#if BYTES_PER_MPI_LIMB == 4 + alimb = a->d[i] ? cpu_to_be32(a->d[i]) : 0; +#elif BYTES_PER_MPI_LIMB == 8 + alimb = a->d[i] ? cpu_to_be64(a->d[i]) : 0; +#else +#error please implement for this limb size. +#endif + p = (u8 *)&alimb; + + for (x = 0; x < sizeof(alimb); x++) { + *p2++ = *p++; + if (!--buf_len) { + sg_miter_next(&miter); + buf_len = miter.length; + p2 = miter.addr; + } + } + } + + sg_miter_stop(&miter); + return 0; +} +EXPORT_SYMBOL_GPL(mpi_write_to_sgl); + +/* + * mpi_read_raw_from_sgl() - Function allocates an MPI and populates it with + * data from the sgl + * + * This function works in the same way as the mpi_read_raw_data, but it + * takes an sgl instead of void * buffer. i.e. it allocates + * a new MPI and reads the content of the sgl to the MPI. + * + * @sgl: scatterlist to read from + * @nbytes: number of bytes to read + * + * Return: Pointer to a new MPI or NULL on error + */ +MPI mpi_read_raw_from_sgl(struct scatterlist *sgl, unsigned int nbytes) +{ + struct sg_mapping_iter miter; + unsigned int nbits, nlimbs; + int x, j, z, lzeros, ents; + unsigned int len; + const u8 *buff; + mpi_limb_t a; + MPI val = NULL; + + ents = sg_nents_for_len(sgl, nbytes); + if (ents < 0) + return NULL; + + sg_miter_start(&miter, sgl, ents, SG_MITER_ATOMIC | SG_MITER_FROM_SG); + + lzeros = 0; + len = 0; + while (nbytes > 0) { + while (len && !*buff && lzeros < nbytes) { + lzeros++; + len--; + buff++; + } + + if (len && *buff) + break; + + sg_miter_next(&miter); + buff = miter.addr; + len = miter.length; + + nbytes -= lzeros; + lzeros = 0; + } + + miter.consumed = lzeros; + + nbytes -= lzeros; + nbits = nbytes * 8; + if (nbits > MAX_EXTERN_MPI_BITS) { + sg_miter_stop(&miter); + pr_info("MPI: mpi too large (%u bits)\n", nbits); + return NULL; + } + + if (nbytes > 0) + nbits -= count_leading_zeros(*buff) - (BITS_PER_LONG - 8); + + sg_miter_stop(&miter); + + nlimbs = DIV_ROUND_UP(nbytes, BYTES_PER_MPI_LIMB); + val = mpi_alloc(nlimbs); + if (!val) + return NULL; + + val->nbits = nbits; + val->sign = 0; + val->nlimbs = nlimbs; + + if (nbytes == 0) + return val; + + j = nlimbs - 1; + a = 0; + z = BYTES_PER_MPI_LIMB - nbytes % BYTES_PER_MPI_LIMB; + z %= BYTES_PER_MPI_LIMB; + + while (sg_miter_next(&miter)) { + buff = miter.addr; + len = min(miter.length, nbytes); + nbytes -= len; + + for (x = 0; x < len; x++) { + a <<= 8; + a |= *buff++; + if (((z + x + 1) % BYTES_PER_MPI_LIMB) == 0) { + val->d[j--] = a; + a = 0; + } + } + z += x; + } + + return val; +} +EXPORT_SYMBOL_GPL(mpi_read_raw_from_sgl); -- cgit v1.3.1