[PATCH] detect close failure on just-written file handles
From: Jim Meyering <hidden>
Date: 2016-06-15 22:43:18
Subsystem:
the rest · Maintainer:
Linus Torvalds
I audited git for potential undetected write failures. In the cases fixed below, the diagnostics I add mimic the diagnostics used in surrounding code, even when that means not reporting the precise strerror(errno) cause of the error. Signed-off-by: Jim Meyering <redacted> --- builtin-init-db.c | 3 ++- builtin-rerere.c | 3 ++- index-pack.c | 3 ++- refs.c | 6 ++---- 4 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/builtin-init-db.c b/builtin-init-db.c
index 0be2d2e..976f47b 100644
--- a/builtin-init-db.c
+++ b/builtin-init-db.c@@ -40,7 +40,8 @@ static int copy_file(const char *dst, const char *src, int mode) return fdo; } status = copy_fd(fdi, fdo); - close(fdo); + if (close(fdo) != 0) + return error("%s: write error: %s", dst, strerror(errno)); if (!status && adjust_shared_perm(dst)) return -1;
diff --git a/builtin-rerere.c b/builtin-rerere.c
index f6409b9..29fb075 100644
--- a/builtin-rerere.c
+++ b/builtin-rerere.c@@ -57,7 +57,8 @@ static int write_rr(struct path_list *rr, int out_fd) write_in_full(out_fd, path, length) != length) die("unable to write rerere record"); } - close(out_fd); + if (close(out_fd) != 0) + die("unable to write rerere record"); return commit_lock_file(&write_lock); }
diff --git a/index-pack.c b/index-pack.c
index 82c8da3..8403c36 100644
--- a/index-pack.c
+++ b/index-pack.c@@ -634,7 +634,8 @@ static void final(const char *final_pack_name, const char *curr_pack_name, write_or_die(keep_fd, keep_msg, keep_msg_len); write_or_die(keep_fd, "\n", 1); } - close(keep_fd); + if (close(keep_fd) != 0) + die("cannot write keep file"); report = "keep"; } }
diff --git a/refs.c b/refs.c
index 67ac97c..4dc7e8b 100644
--- a/refs.c
+++ b/refs.c@@ -1106,8 +1106,7 @@ static int log_ref_write(const char *ref_name, const unsigned char *old_sha1, len += sprintf(logrec + len - 1, "\t%.*s\n", msglen, msg) - 1; written = len <= maxlen ? write_in_full(logfd, logrec, len) : -1; free(logrec); - close(logfd); - if (written != len) + if (close(logfd) != 0 || written != len) return error("Unable to append to %s", log_file); return 0; }
@@ -1204,8 +1203,7 @@ int create_symref(const char *ref_target, const char *refs_heads_master, goto error_free_return; } written = write_in_full(fd, ref, len); - close(fd); - if (written != len) { + if (close(fd) != 0 || written != len) { error("Unable to write to %s", lockpath); goto error_unlink_return; }