From 83911b9e069169fffd82212f478952d474ee1e8d Mon Sep 17 00:00:00 2001 From: "K. Y. Srinivasan" Date: Fri, 27 Mar 2015 00:27:18 -0700 Subject: [PATCH] scsi: storvsc: Fix a bug in copy_from_bounce_buffer() commit 8de580742fee8bc34d116f57a20b22b9a5f08403 upstream. We may exit this function without properly freeing up the maapings we may have acquired. Fix the bug. Signed-off-by: K. Y. Srinivasan Reviewed-by: Long Li Signed-off-by: James Bottomley [bwh: Backported to 3.2: - Adjust filename - Keep using kmap_atomic()/kunmap_atomic(), not the sg_-prefixed functions] Signed-off-by: Ben Hutchings --- drivers/staging/hv/storvsc_drv.c | 15 ++++++++------- 1 file changed, 8 insertions(+), 7 deletions(-) diff --git a/drivers/staging/hv/storvsc_drv.c b/drivers/staging/hv/storvsc_drv.c index c43a9e8ecf21..54ef3d4756f2 100644 --- a/drivers/staging/hv/storvsc_drv.c +++ b/drivers/staging/hv/storvsc_drv.c @@ -940,23 +940,24 @@ static unsigned int copy_to_bounce_buffer(struct scatterlist *orig_sgl, if (bounce_sgl[j].length == PAGE_SIZE) { /* full..move to next entry */ kunmap_atomic((void *)bounce_addr, KM_IRQ0); + bounce_addr = 0; j++; + } - /* if we need to use another bounce buffer */ - if (srclen || i != orig_sgl_count - 1) - bounce_addr = + /* if we need to use another bounce buffer */ + if (srclen && bounce_addr == 0) + bounce_addr = (unsigned long)kmap_atomic( sg_page((&bounce_sgl[j])), KM_IRQ0); - } else if (srclen == 0 && i == orig_sgl_count - 1) { - /* unmap the last bounce that is < PAGE_SIZE */ - kunmap_atomic((void *)bounce_addr, KM_IRQ0); - } } kunmap_atomic((void *)(src_addr - orig_sgl[i].offset), KM_IRQ0); } + if (bounce_addr) + kunmap_atomic((void *)bounce_addr, KM_IRQ0); + local_irq_restore(flags); return total_copied; -- 2.47.2