diff options
Diffstat (limited to 'gnu/packages/patches/libarchive-fix-filesystem-attacks.patch')
| -rw-r--r-- | gnu/packages/patches/libarchive-fix-filesystem-attacks.patch | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/gnu/packages/patches/libarchive-fix-filesystem-attacks.patch b/gnu/packages/patches/libarchive-fix-filesystem-attacks.patch new file mode 100644 index 0000000000..bce63d5e4e --- /dev/null +++ b/gnu/packages/patches/libarchive-fix-filesystem-attacks.patch @@ -0,0 +1,445 @@ +This patch fixes two bugs that allow attackers to overwrite or change +the permissions of arbitrary files: + +https://github.com/libarchive/libarchive/issues/745 +https://github.com/libarchive/libarchive/issues/746 + +Patch copied from upstream repository: + +https://github.com/libarchive/libarchive/commit/dfd6b54ce33960e420fb206d8872fb759b577ad9 + +From dfd6b54ce33960e420fb206d8872fb759b577ad9 Mon Sep 17 00:00:00 2001 +From: Tim Kientzle <kientzle@acm.org> +Date: Sun, 11 Sep 2016 13:21:57 -0700 +Subject: [PATCH] Fixes for Issue #745 and Issue #746 from Doran Moppert. + +--- + libarchive/archive_write_disk_posix.c | 294 ++++++++++++++++++++++++++-------- + 1 file changed, 227 insertions(+), 67 deletions(-) + +diff --git a/libarchive/archive_write_disk_posix.c b/libarchive/archive_write_disk_posix.c +index 8f0421e..abe1a86 100644 +--- a/libarchive/archive_write_disk_posix.c ++++ b/libarchive/archive_write_disk_posix.c +@@ -326,12 +326,14 @@ struct archive_write_disk { + + #define HFS_BLOCKS(s) ((s) >> 12) + ++static int check_symlinks_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags); + static int check_symlinks(struct archive_write_disk *); + static int create_filesystem_object(struct archive_write_disk *); + static struct fixup_entry *current_fixup(struct archive_write_disk *, const char *pathname); + #if defined(HAVE_FCHDIR) && defined(PATH_MAX) + static void edit_deep_directories(struct archive_write_disk *ad); + #endif ++static int cleanup_pathname_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags); + static int cleanup_pathname(struct archive_write_disk *); + static int create_dir(struct archive_write_disk *, char *); + static int create_parent_dir(struct archive_write_disk *, char *); +@@ -2014,6 +2016,10 @@ create_filesystem_object(struct archive_write_disk *a) + const char *linkname; + mode_t final_mode, mode; + int r; ++ /* these for check_symlinks_fsobj */ ++ char *linkname_copy; /* non-const copy of linkname */ ++ struct archive_string error_string; ++ int error_number; + + /* We identify hard/symlinks according to the link names. */ + /* Since link(2) and symlink(2) don't handle modes, we're done here. */ +@@ -2022,6 +2028,27 @@ create_filesystem_object(struct archive_write_disk *a) + #if !HAVE_LINK + return (EPERM); + #else ++ archive_string_init(&error_string); ++ linkname_copy = strdup(linkname); ++ if (linkname_copy == NULL) { ++ return (EPERM); ++ } ++ /* TODO: consider using the cleaned-up path as the link target? */ ++ r = cleanup_pathname_fsobj(linkname_copy, &error_number, &error_string, a->flags); ++ if (r != ARCHIVE_OK) { ++ archive_set_error(&a->archive, error_number, "%s", error_string.s); ++ free(linkname_copy); ++ /* EPERM is more appropriate than error_number for our callers */ ++ return (EPERM); ++ } ++ r = check_symlinks_fsobj(linkname_copy, &error_number, &error_string, a->flags); ++ if (r != ARCHIVE_OK) { ++ archive_set_error(&a->archive, error_number, "%s", error_string.s); ++ free(linkname_copy); ++ /* EPERM is more appropriate than error_number for our callers */ ++ return (EPERM); ++ } ++ free(linkname_copy); + r = link(linkname, a->name) ? errno : 0; + /* + * New cpio and pax formats allow hardlink entries +@@ -2362,115 +2389,228 @@ current_fixup(struct archive_write_disk *a, const char *pathname) + * recent paths. + */ + /* TODO: Extend this to support symlinks on Windows Vista and later. */ ++ ++/* ++ * Checks the given path to see if any elements along it are symlinks. Returns ++ * ARCHIVE_OK if there are none, otherwise puts an error in errmsg. ++ */ + static int +-check_symlinks(struct archive_write_disk *a) ++check_symlinks_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags) + { + #if !defined(HAVE_LSTAT) + /* Platform doesn't have lstat, so we can't look for symlinks. */ + (void)a; /* UNUSED */ ++ (void)path; /* UNUSED */ ++ (void)error_number; /* UNUSED */ ++ (void)error_string; /* UNUSED */ ++ (void)flags; /* UNUSED */ + return (ARCHIVE_OK); + #else +- char *pn; ++ int res = ARCHIVE_OK; ++ char *tail; ++ char *head; ++ int last; + char c; + int r; + struct stat st; ++ int restore_pwd; ++ ++ /* Nothing to do here if name is empty */ ++ if(path[0] == '\0') ++ return (ARCHIVE_OK); + + /* + * Guard against symlink tricks. Reject any archive entry whose + * destination would be altered by a symlink. ++ * ++ * Walk the filename in chunks separated by '/'. For each segment: ++ * - if it doesn't exist, continue ++ * - if it's symlink, abort or remove it ++ * - if it's a directory and it's not the last chunk, cd into it ++ * As we go: ++ * head points to the current (relative) path ++ * tail points to the temporary \0 terminating the segment we're currently examining ++ * c holds what used to be in *tail ++ * last is 1 if this is the last tail + */ +- /* Whatever we checked last time doesn't need to be re-checked. */ +- pn = a->name; +- if (archive_strlen(&(a->path_safe)) > 0) { +- char *p = a->path_safe.s; +- while ((*pn != '\0') && (*p == *pn)) +- ++p, ++pn; +- } ++ restore_pwd = open(".", O_RDONLY | O_BINARY | O_CLOEXEC); ++ __archive_ensure_cloexec_flag(restore_pwd); ++ if (restore_pwd < 0) ++ return (ARCHIVE_FATAL); ++ head = path; ++ tail = path; ++ last = 0; ++ /* TODO: reintroduce a safe cache here? */ + /* Skip the root directory if the path is absolute. */ +- if(pn == a->name && pn[0] == '/') +- ++pn; +- c = pn[0]; +- /* Keep going until we've checked the entire name. */ +- while (pn[0] != '\0' && (pn[0] != '/' || pn[1] != '\0')) { ++ if(tail == path && tail[0] == '/') ++ ++tail; ++ /* Keep going until we've checked the entire name. ++ * head, tail, path all alias the same string, which is ++ * temporarily zeroed at tail, so be careful restoring the ++ * stashed (c=tail[0]) for error messages. ++ * Exiting the loop with break is okay; continue is not. ++ */ ++ while (!last) { ++ /* Skip the separator we just consumed, plus any adjacent ones */ ++ while (*tail == '/') ++ ++tail; + /* Skip the next path element. */ +- while (*pn != '\0' && *pn != '/') +- ++pn; +- c = pn[0]; +- pn[0] = '\0'; ++ while (*tail != '\0' && *tail != '/') ++ ++tail; ++ /* is this the last path component? */ ++ last = (tail[0] == '\0') || (tail[0] == '/' && tail[1] == '\0'); ++ /* temporarily truncate the string here */ ++ c = tail[0]; ++ tail[0] = '\0'; + /* Check that we haven't hit a symlink. */ +- r = lstat(a->name, &st); ++ r = lstat(head, &st); + if (r != 0) { ++ tail[0] = c; + /* We've hit a dir that doesn't exist; stop now. */ + if (errno == ENOENT) { + break; + } else { +- /* Note: This effectively disables deep directory ++ /* Treat any other error as fatal - best to be paranoid here ++ * Note: This effectively disables deep directory + * support when security checks are enabled. + * Otherwise, very long pathnames that trigger + * an error here could evade the sandbox. + * TODO: We could do better, but it would probably + * require merging the symlink checks with the + * deep-directory editing. */ +- return (ARCHIVE_FAILED); ++ if (error_number) *error_number = errno; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Could not stat %s", ++ path); ++ res = ARCHIVE_FAILED; ++ break; ++ } ++ } else if (S_ISDIR(st.st_mode)) { ++ if (!last) { ++ if (chdir(head) != 0) { ++ tail[0] = c; ++ if (error_number) *error_number = errno; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Could not chdir %s", ++ path); ++ res = (ARCHIVE_FATAL); ++ break; ++ } ++ /* Our view is now from inside this dir: */ ++ head = tail + 1; + } + } else if (S_ISLNK(st.st_mode)) { +- if (c == '\0') { ++ if (last) { + /* + * Last element is symlink; remove it + * so we can overwrite it with the + * item being extracted. + */ +- if (unlink(a->name)) { +- archive_set_error(&a->archive, errno, +- "Could not remove symlink %s", +- a->name); +- pn[0] = c; +- return (ARCHIVE_FAILED); ++ if (unlink(head)) { ++ tail[0] = c; ++ if (error_number) *error_number = errno; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Could not remove symlink %s", ++ path); ++ res = ARCHIVE_FAILED; ++ break; + } +- a->pst = NULL; + /* + * Even if we did remove it, a warning + * is in order. The warning is silly, + * though, if we're just replacing one + * symlink with another symlink. + */ +- if (!S_ISLNK(a->mode)) { +- archive_set_error(&a->archive, 0, +- "Removing symlink %s", +- a->name); ++ tail[0] = c; ++ /* FIXME: not sure how important this is to restore ++ if (!S_ISLNK(path)) { ++ if (error_number) *error_number = 0; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Removing symlink %s", ++ path); + } ++ */ + /* Symlink gone. No more problem! */ +- pn[0] = c; +- return (0); +- } else if (a->flags & ARCHIVE_EXTRACT_UNLINK) { ++ res = ARCHIVE_OK; ++ break; ++ } else if (flags & ARCHIVE_EXTRACT_UNLINK) { + /* User asked us to remove problems. */ +- if (unlink(a->name) != 0) { +- archive_set_error(&a->archive, 0, +- "Cannot remove intervening symlink %s", +- a->name); +- pn[0] = c; +- return (ARCHIVE_FAILED); ++ if (unlink(head) != 0) { ++ tail[0] = c; ++ if (error_number) *error_number = 0; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Cannot remove intervening symlink %s", ++ path); ++ res = ARCHIVE_FAILED; ++ break; + } +- a->pst = NULL; ++ tail[0] = c; + } else { +- archive_set_error(&a->archive, 0, +- "Cannot extract through symlink %s", +- a->name); +- pn[0] = c; +- return (ARCHIVE_FAILED); ++ tail[0] = c; ++ if (error_number) *error_number = 0; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Cannot extract through symlink %s", ++ path); ++ res = ARCHIVE_FAILED; ++ break; + } + } +- pn[0] = c; +- if (pn[0] != '\0') +- pn++; /* Advance to the next segment. */ ++ /* be sure to always maintain this */ ++ tail[0] = c; ++ if (tail[0] != '\0') ++ tail++; /* Advance to the next segment. */ + } +- pn[0] = c; +- /* We've checked and/or cleaned the whole path, so remember it. */ +- archive_strcpy(&a->path_safe, a->name); +- return (ARCHIVE_OK); ++ /* Catches loop exits via break */ ++ tail[0] = c; ++#ifdef HAVE_FCHDIR ++ /* If we changed directory above, restore it here. */ ++ if (restore_pwd >= 0) { ++ r = fchdir(restore_pwd); ++ if (r != 0) { ++ if(error_number) *error_number = errno; ++ if(error_string) ++ archive_string_sprintf(error_string, ++ "chdir() failure"); ++ } ++ close(restore_pwd); ++ restore_pwd = -1; ++ if (r != 0) { ++ res = (ARCHIVE_FATAL); ++ } ++ } ++#endif ++ /* TODO: reintroduce a safe cache here? */ ++ return res; + #endif + } + ++/* ++ * Check a->name for symlinks, returning ARCHIVE_OK if its clean, otherwise ++ * calls archive_set_error and returns ARCHIVE_{FATAL,FAILED} ++ */ ++static int ++check_symlinks(struct archive_write_disk *a) ++{ ++ struct archive_string error_string; ++ int error_number; ++ int rc; ++ archive_string_init(&error_string); ++ rc = check_symlinks_fsobj(a->name, &error_number, &error_string, a->flags); ++ if (rc != ARCHIVE_OK) { ++ archive_set_error(&a->archive, error_number, "%s", error_string.s); ++ } ++ archive_string_free(&error_string); ++ a->pst = NULL; /* to be safe */ ++ return rc; ++} ++ ++ + #if defined(__CYGWIN__) + /* + * 1. Convert a path separator from '\' to '/' . +@@ -2544,15 +2684,17 @@ cleanup_pathname_win(struct archive_write_disk *a) + * is set) if the path is absolute. + */ + static int +-cleanup_pathname(struct archive_write_disk *a) ++cleanup_pathname_fsobj(char *path, int *error_number, struct archive_string *error_string, int flags) + { + char *dest, *src; + char separator = '\0'; + +- dest = src = a->name; ++ dest = src = path; + if (*src == '\0') { +- archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, +- "Invalid empty pathname"); ++ if (error_number) *error_number = ARCHIVE_ERRNO_MISC; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Invalid empty pathname"); + return (ARCHIVE_FAILED); + } + +@@ -2561,9 +2703,11 @@ cleanup_pathname(struct archive_write_disk *a) + #endif + /* Skip leading '/'. */ + if (*src == '/') { +- if (a->flags & ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS) { +- archive_set_error(&a->archive, ARCHIVE_ERRNO_MISC, +- "Path is absolute"); ++ if (flags & ARCHIVE_EXTRACT_SECURE_NOABSOLUTEPATHS) { ++ if (error_number) *error_number = ARCHIVE_ERRNO_MISC; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Path is absolute"); + return (ARCHIVE_FAILED); + } + +@@ -2590,10 +2734,11 @@ cleanup_pathname(struct archive_write_disk *a) + } else if (src[1] == '.') { + if (src[2] == '/' || src[2] == '\0') { + /* Conditionally warn about '..' */ +- if (a->flags & ARCHIVE_EXTRACT_SECURE_NODOTDOT) { +- archive_set_error(&a->archive, +- ARCHIVE_ERRNO_MISC, +- "Path contains '..'"); ++ if (flags & ARCHIVE_EXTRACT_SECURE_NODOTDOT) { ++ if (error_number) *error_number = ARCHIVE_ERRNO_MISC; ++ if (error_string) ++ archive_string_sprintf(error_string, ++ "Path contains '..'"); + return (ARCHIVE_FAILED); + } + } +@@ -2624,7 +2769,7 @@ cleanup_pathname(struct archive_write_disk *a) + * We've just copied zero or more path elements, not including the + * final '/'. + */ +- if (dest == a->name) { ++ if (dest == path) { + /* + * Nothing got copied. The path must have been something + * like '.' or '/' or './' or '/././././/./'. +@@ -2639,6 +2784,21 @@ cleanup_pathname(struct archive_write_disk *a) + return (ARCHIVE_OK); + } + ++static int ++cleanup_pathname(struct archive_write_disk *a) ++{ ++ struct archive_string error_string; ++ int error_number; ++ int rc; ++ archive_string_init(&error_string); ++ rc = cleanup_pathname_fsobj(a->name, &error_number, &error_string, a->flags); ++ if (rc != ARCHIVE_OK) { ++ archive_set_error(&a->archive, error_number, "%s", error_string.s); ++ } ++ archive_string_free(&error_string); ++ return rc; ++} ++ + /* + * Create the parent directory of the specified path, assuming path + * is already in mutable storage. |