From: Ye Bin yebin10@huawei.com
hulk inclusion category: bugfix bugzilla: 49978 CVE: NA
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This reverts commit 544058bd9aa143489cd480c5c076caf76c33b6c1.
We got follow error: 2021/02/26 10:15:49 parsed 1 programs 2021/02/26 10:15:49 executed programs: 0
Message from syslogd@localhost at Feb 26 10:15:52 ... kernel:[ 710.135641] page:ffff7e000309e600 count:-1 mapcount:0 mapping:0000000000000000 index:0x0
Message from syslogd@localhost at Feb 26 10:15:52 ... kernel:[ 710.136201] flags: 0xffffe0000000000()
As in sg_remove_scat will judge schp->k_use_sg then free pages. But in sg_build_indirect if (rem_sz > 0) we free pages without clean schp->k_use_sg or set schp->pages[i] with NULL. So it will lead to free in sg_remove_scat again.
Fixes: 544058bd9aa1("scsi: sg: fix memory leak in sg_build_indirect") Signed-off-by: Ye Bin yebin10@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Yang Yingliang yangyingliang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- drivers/scsi/sg.c | 6 +----- 1 file changed, 1 insertion(+), 5 deletions(-)
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 749faafbc977..10da329fa53f 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -1942,12 +1942,8 @@ sg_build_indirect(Sg_scatter_hold * schp, Sg_fd * sfp, int buff_size) k, rem_sz));
schp->bufflen = blk_size; - if (rem_sz > 0) { /* must have failed */ - for (i = 0; i < k; i++) - __free_pages(schp->pages[i], order); - + if (rem_sz > 0) /* must have failed */ return -ENOMEM; - } return 0; out: for (i = 0; i < k; i++)