On 12/18/19 4:44 PM, Yang Yingliang wrote: > When I doing fuzzy test, get the memleak report: > > BUG: memory leak > unreferenced object 0xffff88837af80000 (size 4096): > comm "memleak", pid 3557, jiffies 4294817681 (age 112.499s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 20 00 00 00 10 01 00 00 00 00 00 00 01 00 00 00 ............... > backtrace: > [<000000001c894df8>] bio_alloc_bioset+0x393/0x590 > [<000000008b139a3c>] bio_copy_user_iov+0x300/0xcd0 > [<00000000a998bd8c>] blk_rq_map_user_iov+0x2f1/0x5f0 > [<000000005ceb7f05>] blk_rq_map_user+0xf2/0x160 > [<000000006454da92>] sg_common_write.isra.21+0x1094/0x1870 > [<00000000064bb208>] sg_write.part.25+0x5d9/0x950 > [<000000004fc670f6>] sg_write+0x5f/0x8c > [<00000000b0d05c7b>] __vfs_write+0x7c/0x100 > [<000000008e177714>] vfs_write+0x1c3/0x500 > [<0000000087d23f34>] ksys_write+0xf9/0x200 > [<000000002c8dbc9d>] do_syscall_64+0x9f/0x4f0 > [<00000000678d8e9a>] entry_SYSCALL_64_after_hwframe+0x49/0xbe > > If __blk_rq_map_user_iov() is failed in blk_rq_map_user_iov(), > the bio(s) which is allocated before this failing will leak. The > refcount of the bio(s) is init to 1 and increased to 2 by calling > bio_get(), but __blk_rq_unmap_user() only decrease it to 1, so > the bio cannot be freed. Fix it by calling blk_rq_unmap_user(). > > Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> > Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> Good catch! Looks fine to me. Reviewed-by: Bob Liu <bob.liu@xxxxxxxxxx> > --- > block/blk-map.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/block/blk-map.c b/block/blk-map.c > index 3a62e471d81b..b0790268ed9d 100644 > --- a/block/blk-map.c > +++ b/block/blk-map.c > @@ -151,7 +151,7 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq, > return 0; > > unmap_rq: > - __blk_rq_unmap_user(bio); > + blk_rq_unmap_user(bio); > fail: > rq->bio = NULL; > return ret; >
