From 7e76f34fa103677a27d96a7cfef8ce61389a32de Mon Sep 17 00:00:00 2001 From: Aruna Balakrishnaiah Date: Thu, 8 Aug 2013 22:33:49 +0530 Subject: [PATCH] powerpc/pseries: Fix buffer overflow when reading from pstore When reading from pstore there is a buffer overflow during decompression due to the header added in unzip_oops. Remove unzip_oops and call pstore_decompress directly in nvram_pstore_read. Allocate buffer of size report_length of the oops header as header will not be deallocated in pstore. Since we have 'openssl' command line tool to decompress the compressed data, dump the compressed data in case decompression fails instead of not dumping anything. Signed-off-by: Aruna Balakrishnaiah Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/platforms/pseries/nvram.c | 70 +++++++++----------------- 1 file changed, 24 insertions(+), 46 deletions(-) diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c index 9f8671a44551..893f36053c97 100644 --- a/arch/powerpc/platforms/pseries/nvram.c +++ b/arch/powerpc/platforms/pseries/nvram.c @@ -569,35 +569,6 @@ error: return ret; } -static int unzip_oops(char *oops_buf, char *big_buf) -{ - struct oops_log_info *oops_hdr = (struct oops_log_info *)oops_buf; - u64 timestamp = oops_hdr->timestamp; - char *big_oops_data = NULL; - char *oops_data_buf = NULL; - size_t big_oops_data_sz; - int unzipped_len; - - big_oops_data = big_buf + sizeof(struct oops_log_info); - big_oops_data_sz = big_oops_buf_sz - sizeof(struct oops_log_info); - oops_data_buf = oops_buf + sizeof(struct oops_log_info); - - unzipped_len = nvram_decompress(oops_data_buf, big_oops_data, - oops_hdr->report_length, - big_oops_data_sz); - - if (unzipped_len < 0) { - pr_err("nvram: decompression failed; returned %d\n", - unzipped_len); - return -1; - } - oops_hdr = (struct oops_log_info *)big_buf; - oops_hdr->version = OOPS_HDR_VERSION; - oops_hdr->report_length = (u16) unzipped_len; - oops_hdr->timestamp = timestamp; - return 0; -} - static int nvram_pstore_open(struct pstore_info *psi) { /* Reset the iterator to start reading partitions again */ @@ -685,10 +656,9 @@ static ssize_t nvram_pstore_read(u64 *id, enum pstore_type_id *type, unsigned int err_type, id_no, size = 0; struct nvram_os_partition *part = NULL; char *buff = NULL, *big_buff = NULL; - int rc, sig = 0; + int sig = 0; loff_t p; -read_partition: read_type++; switch (nvram_type_ids[read_type]) { @@ -749,30 +719,36 @@ read_partition: *id = id_no; if (nvram_type_ids[read_type] == PSTORE_TYPE_DMESG) { + int length, unzipped_len; + oops_hdr = (struct oops_log_info *)buff; - *buf = buff + sizeof(*oops_hdr); + length = oops_hdr->report_length; + *buf = kmalloc(length, GFP_KERNEL); + if (*buf == NULL) + return -ENOMEM; + memcpy(*buf, buff + sizeof(*oops_hdr), length); + time->tv_sec = oops_hdr->timestamp; + time->tv_nsec = 0; + kfree(buff); if (err_type == ERR_TYPE_KERNEL_PANIC_GZ) { big_buff = kmalloc(big_oops_buf_sz, GFP_KERNEL); if (!big_buff) return -ENOMEM; - rc = unzip_oops(buff, big_buff); + unzipped_len = nvram_decompress(*buf, big_buff, + length, big_oops_buf_sz); - if (rc != 0) { - kfree(buff); + if (unzipped_len < 0) { + pr_err("nvram: decompression failed, returned " + "rc %d\n", unzipped_len); kfree(big_buff); - goto read_partition; + } else { + *buf = big_buff; + length = unzipped_len; } - - oops_hdr = (struct oops_log_info *)big_buff; - *buf = big_buff + sizeof(*oops_hdr); - kfree(buff); } - - time->tv_sec = oops_hdr->timestamp; - time->tv_nsec = 0; - return oops_hdr->report_length; + return length; } *buf = buff; @@ -816,6 +792,7 @@ static int nvram_pstore_init(void) static void __init nvram_init_oops_partition(int rtas_partition_exists) { int rc; + size_t size; rc = pseries_nvram_init_os_partition(&oops_log_partition); if (rc != 0) { @@ -844,8 +821,9 @@ static void __init nvram_init_oops_partition(int rtas_partition_exists) big_oops_buf_sz = (oops_data_sz * 100) / 45; big_oops_buf = kmalloc(big_oops_buf_sz, GFP_KERNEL); if (big_oops_buf) { - stream.workspace = kmalloc(zlib_deflate_workspacesize( - WINDOW_BITS, MEM_LEVEL), GFP_KERNEL); + size = max(zlib_deflate_workspacesize(WINDOW_BITS, MEM_LEVEL), + zlib_inflate_workspacesize()); + stream.workspace = kmalloc(size, GFP_KERNEL); if (!stream.workspace) { pr_err("nvram: No memory for compression workspace; " "skipping compression of %s partition data\n", -- 2.30.2