From e6c6e235ab87233cf273f536188d842768304c55 Mon Sep 17 00:00:00 2001 From: Mathieu Desnoyers Date: Mon, 23 Sep 2019 14:31:33 -0400 Subject: [PATCH] Fix: lttng-crash: detect truncated files MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Detect truncated files which size is smaller than the ring buffer header. This can be caused by a situation where sessiond is killed with SIGKILL while doing a metadata regenerate command. Without this fix, lttng-crash is killed with a "Bus error" when encountering a truncated file. Fixes: #1166 Signed-off-by: Mathieu Desnoyers Signed-off-by: Jérémie Galarneau --- src/bin/lttng-crash/lttng-crash.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) diff --git a/src/bin/lttng-crash/lttng-crash.c b/src/bin/lttng-crash/lttng-crash.c index 298ed71a4..f12ecfaea 100644 --- a/src/bin/lttng-crash/lttng-crash.c +++ b/src/bin/lttng-crash/lttng-crash.c @@ -498,7 +498,8 @@ int check_magic(const uint8_t *magic) } static -int get_crash_layout(struct lttng_crash_layout *layout, int fd) +int get_crash_layout(struct lttng_crash_layout *layout, int fd, + const char *input_file) { char *map; int ret = 0, unmapret; @@ -509,7 +510,21 @@ int get_crash_layout(struct lttng_crash_layout *layout, int fd) const struct crash_abi_unknown *abi; uint16_t endian; enum lttng_crash_type layout_type; + struct stat stat; + ret = fstat(fd, &stat); + if (ret < 0) { + PERROR("Failed to fstat '%s'", input_file); + return -1; + } + if (stat.st_size < RB_CRASH_DUMP_ABI_LEN) { + ERR("File '%s' truncated: file length of %" PRIi64 + " bytes does not meet the minimal expected " + "length of %d bytes", + input_file, (int64_t) stat.st_size, + RB_CRASH_DUMP_ABI_LEN); + return -1; + } map = mmap(NULL, RB_CRASH_DUMP_ABI_LEN, PROT_READ, MAP_PRIVATE, fd, 0); if (map == MAP_FAILED) { @@ -838,7 +853,7 @@ int extract_file(int output_dir_fd, const char *output_file, } /* Query the crash ABI layout */ - ret = get_crash_layout(&layout, fd_src); + ret = get_crash_layout(&layout, fd_src, input_file); if (ret) { goto close_src; } -- 2.34.1