From 3026c4688ca80d9c5cc1606368c4a1009a6f507d Mon Sep 17 00:00:00 2001 From: Alberto Garcia Date: Tue, 31 Jan 2017 18:09:54 +0200 Subject: [PATCH] qemu-io: don't allow I/O operations larger than BDRV_REQUEST_MAX_BYTES Passing a request size larger than BDRV_REQUEST_MAX_BYTES to any of the I/O commands results in an error. While 'read' and 'write' handle the error correctly, 'aio_read' and 'aio_write' hit an assertion: blk_aio_read_entry: Assertion `rwco->qiov->size == acb->bytes' failed. The reason is that the QEMU I/O code cannot handle request sizes larger than BDRV_REQUEST_MAX_BYTES, so this patch makes qemu-io check that all values are within range. Signed-off-by: Alberto Garcia Message-id: 79f66648c685929a144396bda24d13a207131dcf.1485878688.git.berto@igalia.com [mreitz: Use BDRV_REQUEST_MAX_BYTES instead of INT_MAX] Signed-off-by: Max Reitz --- qemu-io-cmds.c | 20 +++++++++++++------- 1 file changed, 13 insertions(+), 7 deletions(-) diff --git a/qemu-io-cmds.c b/qemu-io-cmds.c index 95bcde1d88..e415b03cd0 100644 --- a/qemu-io-cmds.c +++ b/qemu-io-cmds.c @@ -388,9 +388,15 @@ create_iovec(BlockBackend *blk, QEMUIOVector *qiov, char **argv, int nr_iov, goto fail; } - if (len > SIZE_MAX) { - printf("Argument '%s' exceeds maximum size %llu\n", arg, - (unsigned long long)SIZE_MAX); + if (len > BDRV_REQUEST_MAX_BYTES) { + printf("Argument '%s' exceeds maximum size %" PRIu64 "\n", arg, + (uint64_t)BDRV_REQUEST_MAX_BYTES); + goto fail; + } + + if (count > BDRV_REQUEST_MAX_BYTES - len) { + printf("The total number of bytes exceed the maximum size %" PRIu64 + "\n", (uint64_t)BDRV_REQUEST_MAX_BYTES); goto fail; } @@ -682,9 +688,9 @@ static int read_f(BlockBackend *blk, int argc, char **argv) if (count < 0) { print_cvtnum_err(count, argv[optind]); return 0; - } else if (count > SIZE_MAX) { + } else if (count > BDRV_REQUEST_MAX_BYTES) { printf("length cannot exceed %" PRIu64 ", given %s\n", - (uint64_t) SIZE_MAX, argv[optind]); + (uint64_t)BDRV_REQUEST_MAX_BYTES, argv[optind]); return 0; } @@ -1004,9 +1010,9 @@ static int write_f(BlockBackend *blk, int argc, char **argv) if (count < 0) { print_cvtnum_err(count, argv[optind]); return 0; - } else if (count > SIZE_MAX) { + } else if (count > BDRV_REQUEST_MAX_BYTES) { printf("length cannot exceed %" PRIu64 ", given %s\n", - (uint64_t) SIZE_MAX, argv[optind]); + (uint64_t)BDRV_REQUEST_MAX_BYTES, argv[optind]); return 0; }