[PATCH v8 2/5] setup: sanity check file size in read_gitfile_gently
flat view
STALE3767d
From: Erik Elfström <hidden>
Date: 2016-06-15 23:05:19
Subsystem:
the rest · Maintainer:
Linus Torvalds
Revision v8 of 8 in this series.
Revisions (8)
read_gitfile_gently will allocate a buffer to fit the entire file that should be read. Add a sanity check of the file size before opening to avoid allocating a potentially huge amount of memory if we come across a large file that someone happened to name ".git". The limit is set to a sufficiently unreasonable size that should never be exceeded by a genuine .git file. Signed-off-by: Erik Elfström <redacted> --- cache.h | 1 + setup.c | 7 +++++++ 2 files changed, 8 insertions(+)
diff --git a/cache.h b/cache.h
index 25578cb..858d9b3 100644
--- a/cache.h
+++ b/cache.h@@ -454,6 +454,7 @@ extern const char *get_git_work_tree(void); #define READ_GITFILE_ERR_INVALID_FORMAT 5 #define READ_GITFILE_ERR_NO_PATH 6 #define READ_GITFILE_ERR_NOT_A_REPO 7 +#define READ_GITFILE_ERR_TOO_LARGE 8 extern const char *read_gitfile_gently(const char *path, int *return_error_code); #define read_gitfile(path) read_gitfile_gently((path), NULL) extern const char *resolve_gitdir(const char *suspect);
diff --git a/setup.c b/setup.c
index 4748b63..a03ca94 100644
--- a/setup.c
+++ b/setup.c@@ -414,6 +414,7 @@ static void update_linked_gitdir(const char *gitfile, const char *gitdir) */ const char *read_gitfile_gently(const char *path, int *return_error_code) { + const int max_file_size = 1 << 20; /* 1MB */ int error_code = 0; char *buf = NULL; char *dir = NULL;
@@ -430,6 +431,10 @@ const char *read_gitfile_gently(const char *path, int *return_error_code) error_code = READ_GITFILE_ERR_NOT_A_FILE; goto cleanup_return; } + if (st.st_size > max_file_size) { + error_code = READ_GITFILE_ERR_TOO_LARGE; + goto cleanup_return; + } fd = open(path, O_RDONLY); if (fd < 0) { error_code = READ_GITFILE_ERR_OPEN_FAILED;
@@ -489,6 +494,8 @@ cleanup_return: return NULL; case READ_GITFILE_ERR_OPEN_FAILED: die_errno("Error opening '%s'", path); + case READ_GITFILE_ERR_TOO_LARGE: + die("Too large to be a .git file: '%s'", path); case READ_GITFILE_ERR_READ_FAILED: die("Error reading %s", path); case READ_GITFILE_ERR_INVALID_FORMAT:
--
2.4.3.373.gc496bfb.dirty