From 7262d3c7280343601ab3b0be0d469ffb867b86d7 Mon Sep 17 00:00:00 2001 From: Markus Armbruster Date: Fri, 31 Oct 2014 16:29:55 +0100 Subject: [PATCH 18/19] ide: Treat read/write beyond end as invalid Message-id: <1414772996-17272-5-git-send-email-armbru@redhat.com> Patchwork-id: 62015 O-Subject: [PATCH RHEL-7.1 qemu-kvm 4/5] ide: Treat read/write beyond end as invalid Bugzilla: 1085232 RH-Acked-by: Paolo Bonzini RH-Acked-by: Fam Zheng The block layer fails such reads and writes just fine. However, they then get treated like valid operations that fail: the error action gets executed. Unwanted; reporting the error to the guest is the only sensible action. Reject them before passing them to the block layer. This bypasses the error action and I/O accounting. Not quite correct for DMA, because DMA can fail after some success, and when that happens, the part that succeeded isn't counted. Tolerable, because I/O accounting is an inconsistent mess anyway. Signed-off-by: Markus Armbruster Signed-off-by: Kevin Wolf (cherry picked from commit 58ac321135af890b503ebe56d0d00e184779918f) Signed-off-by: Miroslav Rezanina --- hw/ide/core.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/hw/ide/core.c b/hw/ide/core.c index 98128fb..4c36f52 100644 --- a/hw/ide/core.c +++ b/hw/ide/core.c @@ -513,6 +513,18 @@ static void ide_rw_error(IDEState *s) { ide_set_irq(s->bus); } +static bool ide_sect_range_ok(IDEState *s, + uint64_t sector, uint64_t nb_sectors) +{ + uint64_t total_sectors; + + bdrv_get_geometry(s->bs, &total_sectors); + if (sector > total_sectors || nb_sectors > total_sectors - sector) { + return false; + } + return true; +} + static void ide_sector_read_cb(void *opaque, int ret) { IDEState *s = opaque; @@ -568,6 +580,11 @@ void ide_sector_read(IDEState *s) printf("sector=%" PRId64 "\n", sector_num); #endif + if (!ide_sect_range_ok(s, sector_num, n)) { + ide_rw_error(s); + return; + } + s->iov.iov_base = s->io_buffer; s->iov.iov_len = n * BDRV_SECTOR_SIZE; qemu_iovec_init_external(&s->qiov, &s->iov, 1); @@ -685,6 +702,12 @@ void ide_dma_cb(void *opaque, int ret) sector_num, n, s->dma_cmd); #endif + if (!ide_sect_range_ok(s, sector_num, n)) { + dma_buf_commit(s); + ide_dma_error(s); + return; + } + switch (s->dma_cmd) { case IDE_DMA_READ: s->bus->dma->aiocb = dma_bdrv_read(s->bs, &s->sg, sector_num, @@ -804,6 +827,11 @@ void ide_sector_write(IDEState *s) n = s->req_nb_sectors; } + if (!ide_sect_range_ok(s, sector_num, n)) { + ide_rw_error(s); + return; + } + s->iov.iov_base = s->io_buffer; s->iov.iov_len = n * BDRV_SECTOR_SIZE; qemu_iovec_init_external(&s->qiov, &s->iov, 1); -- 1.8.3.1