From 868f036fee4b1f934117197fb93461d2c968ffec Mon Sep 17 00:00:00 2001 From: Dan Williams Date: Fri, 16 Dec 2016 08:10:31 -0800 Subject: libnvdimm: fix mishandled nvdimm_clear_poison() return value Colin, via static analysis, reports that the length could be negative from nvdimm_clear_poison() in the error case. There was a similar problem with commit 0a3f27b9a6a8 "libnvdimm, namespace: avoid multiple sector calculations" that I noticed when merging the for-4.10/libnvdimm topic branch into libnvdimm-for-next, but I missed this one. Fix both of them to the following procedure: * if we clear a block's worth of media, clear that many blocks in badblocks * if we clear less than the requested size of the transfer return an error * always invalidate cache after any non-error / non-zero nvdimm_clear_poison result Fixes: 82bf1037f2ca ("libnvdimm: check and clear poison before writing to pmem") Fixes: 0a3f27b9a6a8 ("libnvdimm, namespace: avoid multiple sector calculations") Cc: Fabian Frederick Cc: Dave Jiang Reported-by: Colin Ian King Signed-off-by: Dan Williams --- drivers/nvdimm/pmem.c | 21 ++++++++++++++------- 1 file changed, 14 insertions(+), 7 deletions(-) (limited to 'drivers/nvdimm/pmem.c') diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c index bcc359a..ecf79fd 100644 --- a/drivers/nvdimm/pmem.c +++ b/drivers/nvdimm/pmem.c @@ -47,22 +47,29 @@ static struct nd_region *to_region(struct pmem_device *pmem) return to_nd_region(to_dev(pmem)->parent); } -static void pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, +static int pmem_clear_poison(struct pmem_device *pmem, phys_addr_t offset, unsigned int len) { struct device *dev = to_dev(pmem); - sector_t sector, cleared; + sector_t sector; + long cleared; + int rc = 0; sector = (offset - pmem->data_offset) / 512; - cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len) / 512; - if (cleared) { - dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", - __func__, (unsigned long long) sector, - cleared, cleared > 1 ? "s" : ""); + cleared = nvdimm_clear_poison(dev, pmem->phys_addr + offset, len); + if (cleared < len) + rc = -EIO; + if (cleared > 0 && cleared / 512) { + cleared /= 512; + dev_dbg(dev, "%s: %#llx clear %ld sector%s\n", __func__, + (unsigned long long) sector, cleared, + cleared > 1 ? "s" : ""); badblocks_clear(&pmem->bb, sector, cleared); } invalidate_pmem(pmem->virt_addr + offset, len); + + return rc; } static void write_pmem(void *pmem_addr, struct page *page, -- cgit v1.1