diff options
Diffstat (limited to 'meta/recipes-bsp/grub/files/CVE-2020-27749.patch')
| -rw-r--r-- | meta/recipes-bsp/grub/files/CVE-2020-27749.patch | 609 |
1 files changed, 609 insertions, 0 deletions
diff --git a/meta/recipes-bsp/grub/files/CVE-2020-27749.patch b/meta/recipes-bsp/grub/files/CVE-2020-27749.patch new file mode 100644 index 0000000000..a2566b2ded --- /dev/null +++ b/meta/recipes-bsp/grub/files/CVE-2020-27749.patch @@ -0,0 +1,609 @@ +From 4ea7bae51f97e49c84dc67ea30b466ca8633b9f6 Mon Sep 17 00:00:00 2001 +From: Chris Coulson <chris.coulson@canonical.com> +Date: Thu, 7 Jan 2021 19:21:03 +0000 +Subject: kern/parser: Fix a stack buffer overflow + +grub_parser_split_cmdline() expands variable names present in the supplied +command line in to their corresponding variable contents and uses a 1 kiB +stack buffer for temporary storage without sufficient bounds checking. If +the function is called with a command line that references a variable with +a sufficiently large payload, it is possible to overflow the stack +buffer via tab completion, corrupt the stack frame and potentially +control execution. + +Fixes: CVE-2020-27749 + +Reported-by: Chris Coulson <chris.coulson@canonical.com> +Signed-off-by: Chris Coulson <chris.coulson@canonical.com> +Signed-off-by: Darren Kenny <darren.kenny@oracle.com> +Reviewed-by: Daniel Kiper <daniel.kiper@oracle.com> + +Upstream-Status: Backport [https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=c6c426e5ab6ea715153b72584de6bd8c82f698ec && https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=b1c9e9e889e4273fb15712051c887e6078511448 && https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=3d157bbd06506b170fde5ec23980c4bf9f7660e2 && https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=8bc817014ce3d7a498db44eae33c8b90e2430926 && https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=030fb6c4fa354cdbd6a8d6903dfed5d36eaf3cb2 && https://git.savannah.gnu.org/cgit/grub.git/commit/?h=grub-2.06&id=4ea7bae51f97e49c84dc67ea30b466ca8633b9f6] +CVE: CVE-2020-27749 + +Signed-off-by: Hitendra Prajapati <hprajapati@mvista.com> +--- + grub-core/Makefile.core.def | 1 + + grub-core/kern/buffer.c | 117 +++++++++++++++++++++ + grub-core/kern/parser.c | 204 +++++++++++++++++++++++------------- + include/grub/buffer.h | 144 +++++++++++++++++++++++++ + 4 files changed, 395 insertions(+), 71 deletions(-) + create mode 100644 grub-core/kern/buffer.c + create mode 100644 include/grub/buffer.h + +diff --git a/grub-core/Makefile.core.def b/grub-core/Makefile.core.def +index 651ea2a..823cd57 100644 +--- a/grub-core/Makefile.core.def ++++ b/grub-core/Makefile.core.def +@@ -123,6 +123,7 @@ kernel = { + riscv32_efi_startup = kern/riscv/efi/startup.S; + riscv64_efi_startup = kern/riscv/efi/startup.S; + ++ common = kern/buffer.c; + common = kern/command.c; + common = kern/corecmd.c; + common = kern/device.c; +diff --git a/grub-core/kern/buffer.c b/grub-core/kern/buffer.c +new file mode 100644 +index 0000000..9f5f8b8 +--- /dev/null ++++ b/grub-core/kern/buffer.c +@@ -0,0 +1,117 @@ ++/* ++ * GRUB -- GRand Unified Bootloader ++ * Copyright (C) 2021 Free Software Foundation, Inc. ++ * ++ * GRUB 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 3 of the License, or ++ * (at your option) any later version. ++ * ++ * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. ++ */ ++ ++#include <grub/buffer.h> ++#include <grub/err.h> ++#include <grub/misc.h> ++#include <grub/mm.h> ++#include <grub/safemath.h> ++#include <grub/types.h> ++ ++grub_buffer_t ++grub_buffer_new (grub_size_t sz) ++{ ++ struct grub_buffer *ret; ++ ++ ret = (struct grub_buffer *) grub_malloc (sizeof (*ret)); ++ if (ret == NULL) ++ return NULL; ++ ++ ret->data = (grub_uint8_t *) grub_malloc (sz); ++ if (ret->data == NULL) ++ { ++ grub_free (ret); ++ return NULL; ++ } ++ ++ ret->sz = sz; ++ ret->pos = 0; ++ ret->used = 0; ++ ++ return ret; ++} ++ ++void ++grub_buffer_free (grub_buffer_t buf) ++{ ++ grub_free (buf->data); ++ grub_free (buf); ++} ++ ++grub_err_t ++grub_buffer_ensure_space (grub_buffer_t buf, grub_size_t req) ++{ ++ grub_uint8_t *d; ++ grub_size_t newsz = 1; ++ ++ /* Is the current buffer size adequate? */ ++ if (buf->sz >= req) ++ return GRUB_ERR_NONE; ++ ++ /* Find the smallest power-of-2 size that satisfies the request. */ ++ while (newsz < req) ++ { ++ if (newsz == 0) ++ return grub_error (GRUB_ERR_OUT_OF_RANGE, ++ N_("requested buffer size is too large")); ++ newsz <<= 1; ++ } ++ ++ d = (grub_uint8_t *) grub_realloc (buf->data, newsz); ++ if (d == NULL) ++ return grub_errno; ++ ++ buf->data = d; ++ buf->sz = newsz; ++ ++ return GRUB_ERR_NONE; ++} ++ ++void * ++grub_buffer_take_data (grub_buffer_t buf) ++{ ++ void *data = buf->data; ++ ++ buf->data = NULL; ++ buf->sz = buf->pos = buf->used = 0; ++ ++ return data; ++} ++ ++void ++grub_buffer_reset (grub_buffer_t buf) ++{ ++ buf->pos = buf->used = 0; ++} ++ ++grub_err_t ++grub_buffer_advance_read_pos (grub_buffer_t buf, grub_size_t n) ++{ ++ grub_size_t newpos; ++ ++ if (grub_add (buf->pos, n, &newpos)) ++ return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected")); ++ ++ if (newpos > buf->used) ++ return grub_error (GRUB_ERR_OUT_OF_RANGE, ++ N_("new read is position beyond the end of the written data")); ++ ++ buf->pos = newpos; ++ ++ return GRUB_ERR_NONE; ++} +diff --git a/grub-core/kern/parser.c b/grub-core/kern/parser.c +index d1cf061..6ab7aa4 100644 +--- a/grub-core/kern/parser.c ++++ b/grub-core/kern/parser.c +@@ -1,7 +1,7 @@ + /* parser.c - the part of the parser that can return partial tokens */ + /* + * GRUB -- GRand Unified Bootloader +- * Copyright (C) 2005,2007,2009 Free Software Foundation, Inc. ++ * Copyright (C) 2005,2007,2009,2021 Free Software Foundation, Inc. + * + * GRUB is free software: you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by +@@ -18,6 +18,7 @@ + */ + + #include <grub/parser.h> ++#include <grub/buffer.h> + #include <grub/env.h> + #include <grub/misc.h> + #include <grub/mm.h> +@@ -107,8 +108,8 @@ check_varstate (grub_parser_state_t s) + } + + +-static void +-add_var (char *varname, char **bp, char **vp, ++static grub_err_t ++add_var (grub_buffer_t varname, grub_buffer_t buf, + grub_parser_state_t state, grub_parser_state_t newstate) + { + const char *val; +@@ -116,17 +117,74 @@ add_var (char *varname, char **bp, char **vp, + /* Check if a variable was being read in and the end of the name + was reached. */ + if (!(check_varstate (state) && !check_varstate (newstate))) +- return; ++ return GRUB_ERR_NONE; ++ ++ if (grub_buffer_append_char (varname, '\0') != GRUB_ERR_NONE) ++ return grub_errno; + +- *((*vp)++) = '\0'; +- val = grub_env_get (varname); +- *vp = varname; ++ val = grub_env_get ((const char *) grub_buffer_peek_data (varname)); ++ grub_buffer_reset (varname); + if (!val) +- return; ++ return GRUB_ERR_NONE; + + /* Insert the contents of the variable in the buffer. */ +- for (; *val; val++) +- *((*bp)++) = *val; ++ return grub_buffer_append_data (buf, val, grub_strlen (val)); ++} ++ ++static grub_err_t ++terminate_arg (grub_buffer_t buffer, int *argc) ++{ ++ grub_size_t unread = grub_buffer_get_unread_bytes (buffer); ++ ++ if (unread == 0) ++ return GRUB_ERR_NONE; ++ ++ if (*(const char *) grub_buffer_peek_data_at (buffer, unread - 1) == '\0') ++ return GRUB_ERR_NONE; ++ ++ if (grub_buffer_append_char (buffer, '\0') != GRUB_ERR_NONE) ++ return grub_errno; ++ ++ (*argc)++; ++ ++ return GRUB_ERR_NONE; ++} ++ ++static grub_err_t ++process_char (char c, grub_buffer_t buffer, grub_buffer_t varname, ++ grub_parser_state_t state, int *argc, ++ grub_parser_state_t *newstate) ++{ ++ char use; ++ ++ *newstate = grub_parser_cmdline_state (state, c, &use); ++ ++ /* ++ * If a variable was being processed and this character does ++ * not describe the variable anymore, write the variable to ++ * the buffer. ++ */ ++ if (add_var (varname, buffer, state, *newstate) != GRUB_ERR_NONE) ++ return grub_errno; ++ ++ if (check_varstate (*newstate)) ++ { ++ if (use) ++ return grub_buffer_append_char (varname, use); ++ } ++ else if (*newstate == GRUB_PARSER_STATE_TEXT && ++ state != GRUB_PARSER_STATE_ESC && grub_isspace (use)) ++ { ++ /* ++ * Don't add more than one argument if multiple ++ * spaces are used. ++ */ ++ return terminate_arg (buffer, argc); ++ } ++ else if (use) ++ return grub_buffer_append_char (buffer, use); ++ ++ return GRUB_ERR_NONE; + } + + grub_err_t +@@ -135,24 +193,36 @@ grub_parser_split_cmdline (const char *cmdline, + int *argc, char ***argv) + { + grub_parser_state_t state = GRUB_PARSER_STATE_TEXT; +- /* XXX: Fixed size buffer, perhaps this buffer should be dynamically +- allocated. */ +- char buffer[1024]; +- char *bp = buffer; ++ grub_buffer_t buffer, varname; + char *rd = (char *) cmdline; +- char varname[200]; +- char *vp = varname; +- char *args; ++ char *rp = rd; + int i; + + *argc = 0; + *argv = NULL; ++ ++ buffer = grub_buffer_new (1024); ++ if (buffer == NULL) ++ return grub_errno; ++ ++ varname = grub_buffer_new (200); ++ if (varname == NULL) ++ goto fail; ++ + do + { +- if (!rd || !*rd) ++ if (rp == NULL || *rp == '\0') + { ++ if (rd != cmdline) ++ { ++ grub_free (rd); ++ rd = rp = NULL; ++ } + if (getline) +- getline (&rd, 1, getline_data); ++ { ++ getline (&rd, 1, getline_data); ++ rp = rd; ++ } + else + break; + } +@@ -160,39 +230,14 @@ grub_parser_split_cmdline (const char *cmdline, + if (!rd) + break; + +- for (; *rd; rd++) ++ for (; *rp != '\0'; rp++) + { + grub_parser_state_t newstate; +- char use; + +- newstate = grub_parser_cmdline_state (state, *rd, &use); ++ if (process_char (*rp, buffer, varname, state, argc, ++ &newstate) != GRUB_ERR_NONE) ++ goto fail; + +- /* If a variable was being processed and this character does +- not describe the variable anymore, write the variable to +- the buffer. */ +- add_var (varname, &bp, &vp, state, newstate); +- +- if (check_varstate (newstate)) +- { +- if (use) +- *(vp++) = use; +- } +- else +- { +- if (newstate == GRUB_PARSER_STATE_TEXT +- && state != GRUB_PARSER_STATE_ESC && grub_isspace (use)) +- { +- /* Don't add more than one argument if multiple +- spaces are used. */ +- if (bp != buffer && *(bp - 1)) +- { +- *(bp++) = '\0'; +- (*argc)++; +- } +- } +- else if (use) +- *(bp++) = use; +- } + state = newstate; + } + } +@@ -200,43 +245,60 @@ grub_parser_split_cmdline (const char *cmdline, + + /* A special case for when the last character was part of a + variable. */ +- add_var (varname, &bp, &vp, state, GRUB_PARSER_STATE_TEXT); ++ if (add_var (varname, buffer, state, GRUB_PARSER_STATE_TEXT) != GRUB_ERR_NONE) ++ goto fail; + +- if (bp != buffer && *(bp - 1)) +- { +- *(bp++) = '\0'; +- (*argc)++; +- } ++ /* Ensure that the last argument is terminated. */ ++ if (terminate_arg (buffer, argc) != GRUB_ERR_NONE) ++ goto fail; + + /* If there are no args, then we're done. */ + if (!*argc) +- return 0; +- +- /* Reserve memory for the return values. */ +- args = grub_malloc (bp - buffer); +- if (!args) +- return grub_errno; +- grub_memcpy (args, buffer, bp - buffer); ++ { ++ grub_errno = GRUB_ERR_NONE; ++ goto out; ++ } + + *argv = grub_calloc (*argc + 1, sizeof (char *)); + if (!*argv) +- { +- grub_free (args); +- return grub_errno; +- } ++ goto fail; + + /* The arguments are separated with 0's, setup argv so it points to + the right values. */ +- bp = args; + for (i = 0; i < *argc; i++) + { +- (*argv)[i] = bp; +- while (*bp) +- bp++; +- bp++; ++ char *arg; ++ ++ if (i > 0) ++ { ++ if (grub_buffer_advance_read_pos (buffer, 1) != GRUB_ERR_NONE) ++ goto fail; ++ } ++ ++ arg = (char *) grub_buffer_peek_data (buffer); ++ if (arg == NULL || ++ grub_buffer_advance_read_pos (buffer, grub_strlen (arg)) != GRUB_ERR_NONE) ++ goto fail; ++ ++ (*argv)[i] = arg; + } + +- return 0; ++ /* Keep memory for the return values. */ ++ grub_buffer_take_data (buffer); ++ ++ grub_errno = GRUB_ERR_NONE; ++ ++ out: ++ if (rd != cmdline) ++ grub_free (rd); ++ grub_buffer_free (buffer); ++ grub_buffer_free (varname); ++ ++ return grub_errno; ++ ++ fail: ++ grub_free (*argv); ++ goto out; + } + + /* Helper for grub_parser_execute. */ +diff --git a/include/grub/buffer.h b/include/grub/buffer.h +new file mode 100644 +index 0000000..f4b10cf +--- /dev/null ++++ b/include/grub/buffer.h +@@ -0,0 +1,144 @@ ++/* ++ * GRUB -- GRand Unified Bootloader ++ * Copyright (C) 2021 Free Software Foundation, Inc. ++ * ++ * GRUB 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 3 of the License, or ++ * (at your option) any later version. ++ * ++ * GRUB 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 GRUB. If not, see <http://www.gnu.org/licenses/>. ++ */ ++ ++#ifndef GRUB_BUFFER_H ++#define GRUB_BUFFER_H 1 ++ ++#include <grub/err.h> ++#include <grub/misc.h> ++#include <grub/mm.h> ++#include <grub/safemath.h> ++#include <grub/types.h> ++ ++struct grub_buffer ++{ ++ grub_uint8_t *data; ++ grub_size_t sz; ++ grub_size_t pos; ++ grub_size_t used; ++}; ++ ++/* ++ * grub_buffer_t represents a simple variable sized byte buffer with ++ * read and write cursors. It currently only implements ++ * functionality required by the only user in GRUB (append byte[s], ++ * peeking data at a specified position and updating the read cursor. ++ * Some things that this doesn't do yet are: ++ * - Reading a portion of the buffer by copying data from the current ++ * read position in to a caller supplied destination buffer and then ++ * automatically updating the read cursor. ++ * - Dropping the read part at the start of the buffer when an append ++ * requires more space. ++ */ ++typedef struct grub_buffer *grub_buffer_t; ++ ++/* Allocate a new buffer with the specified initial size. */ ++extern grub_buffer_t grub_buffer_new (grub_size_t sz); ++ ++/* Free the buffer and its resources. */ ++extern void grub_buffer_free (grub_buffer_t buf); ++ ++/* Return the number of unread bytes in this buffer. */ ++static inline grub_size_t ++grub_buffer_get_unread_bytes (grub_buffer_t buf) ++{ ++ return buf->used - buf->pos; ++} ++ ++/* ++ * Ensure that the buffer size is at least the requested ++ * number of bytes. ++ */ ++extern grub_err_t grub_buffer_ensure_space (grub_buffer_t buf, grub_size_t req); ++ ++/* ++ * Append the specified number of bytes from the supplied ++ * data to the buffer. ++ */ ++static inline grub_err_t ++grub_buffer_append_data (grub_buffer_t buf, const void *data, grub_size_t len) ++{ ++ grub_size_t req; ++ ++ if (grub_add (buf->used, len, &req)) ++ return grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected")); ++ ++ if (grub_buffer_ensure_space (buf, req) != GRUB_ERR_NONE) ++ return grub_errno; ++ ++ grub_memcpy (&buf->data[buf->used], data, len); ++ buf->used = req; ++ ++ return GRUB_ERR_NONE; ++} ++ ++/* Append the supplied character to the buffer. */ ++static inline grub_err_t ++grub_buffer_append_char (grub_buffer_t buf, char c) ++{ ++ return grub_buffer_append_data (buf, &c, 1); ++} ++ ++/* ++ * Forget and return the underlying data buffer. The caller ++ * becomes the owner of this buffer, and must free it when it ++ * is no longer required. ++ */ ++extern void *grub_buffer_take_data (grub_buffer_t buf); ++ ++/* Reset this buffer. Note that this does not deallocate any resources. */ ++void grub_buffer_reset (grub_buffer_t buf); ++ ++/* ++ * Return a pointer to the underlying data buffer at the specified ++ * offset from the current read position. Note that this pointer may ++ * become invalid if the buffer is mutated further. ++ */ ++static inline void * ++grub_buffer_peek_data_at (grub_buffer_t buf, grub_size_t off) ++{ ++ if (grub_add (buf->pos, off, &off)) ++ { ++ grub_error (GRUB_ERR_OUT_OF_RANGE, N_("overflow is detected.")); ++ return NULL; ++ } ++ ++ if (off >= buf->used) ++ { ++ grub_error (GRUB_ERR_OUT_OF_RANGE, N_("peek out of range")); ++ return NULL; ++ } ++ ++ return &buf->data[off]; ++} ++ ++/* ++ * Return a pointer to the underlying data buffer at the current ++ * read position. Note that this pointer may become invalid if the ++ * buffer is mutated further. ++ */ ++static inline void * ++grub_buffer_peek_data (grub_buffer_t buf) ++{ ++ return grub_buffer_peek_data_at (buf, 0); ++} ++ ++/* Advance the read position by the specified number of bytes. */ ++extern grub_err_t grub_buffer_advance_read_pos (grub_buffer_t buf, grub_size_t n); ++ ++#endif /* GRUB_BUFFER_H */ +-- +2.25.1 + |