| Message ID | 20171108162944.7415-1-ddiss@suse.de (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Nov 08, 2017 at 05:29:44PM +0100, David Disseldorp wrote: > null_alloc_dev() allocates memory for dev->badblocks, but cleanup > currently only occurs in the configfs release codepath, missing a number > of other places. > > This bug was found running the blktests block/010 test, alongside > kmemleak: > rapido1:/blktests# ./check block/010 > ... > rapido1:/blktests# echo scan > /sys/kernel/debug/kmemleak > [ 306.966708] kmemleak: 32 new suspected memory leaks (see /sys/kernel/debug/kmemleak) > rapido1:/blktests# cat /sys/kernel/debug/kmemleak > unreferenced object 0xffff88001f86d000 (size 4096): > comm "modprobe", pid 231, jiffies 4294892415 (age 318.252s) > hex dump (first 32 bytes): > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ > backtrace: > [<ffffffff814b0379>] kmemleak_alloc+0x49/0xa0 > [<ffffffff810f180f>] kmem_cache_alloc+0x9f/0xe0 > [<ffffffff8124e45f>] badblocks_init+0x2f/0x60 > [<ffffffffa0019fae>] 0xffffffffa0019fae > [<ffffffffa0021273>] nullb_device_badblocks_store+0x63/0x130 [null_blk] > [<ffffffff810004cd>] do_one_initcall+0x3d/0x170 > [<ffffffff8109fe0d>] do_init_module+0x56/0x1e9 > [<ffffffff8109ebd7>] load_module+0x1c47/0x26a0 > [<ffffffff8109f819>] SyS_finit_module+0xa9/0xd0 > [<ffffffff814b4f60>] entry_SYSCALL_64_fastpath+0x13/0x94 > > Fixes: 2f54a613c942 ("nullb: badbblocks support") > Signed-off-by: David Disseldorp <ddiss@suse.de> Reviewed-by: Shaohua Li <shli@fb.com> > --- > drivers/block/null_blk.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c > index 8042c26ea9e6..fc80354477c6 100644 > --- a/drivers/block/null_blk.c > +++ b/drivers/block/null_blk.c > @@ -467,7 +467,6 @@ static void nullb_device_release(struct config_item *item) > { > struct nullb_device *dev = to_nullb_device(item); > > - badblocks_exit(&dev->badblocks); > null_free_device_storage(dev, false); > null_free_dev(dev); > } > @@ -578,6 +577,10 @@ static struct nullb_device *null_alloc_dev(void) > > static void null_free_dev(struct nullb_device *dev) > { > + if (!dev) > + return; > + > + badblocks_exit(&dev->badblocks); > kfree(dev); > } > > -- > 2.13.6 >
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c index 8042c26ea9e6..fc80354477c6 100644 --- a/drivers/block/null_blk.c +++ b/drivers/block/null_blk.c @@ -467,7 +467,6 @@ static void nullb_device_release(struct config_item *item) { struct nullb_device *dev = to_nullb_device(item); - badblocks_exit(&dev->badblocks); null_free_device_storage(dev, false); null_free_dev(dev); } @@ -578,6 +577,10 @@ static struct nullb_device *null_alloc_dev(void) static void null_free_dev(struct nullb_device *dev) { + if (!dev) + return; + + badblocks_exit(&dev->badblocks); kfree(dev); }
null_alloc_dev() allocates memory for dev->badblocks, but cleanup currently only occurs in the configfs release codepath, missing a number of other places. This bug was found running the blktests block/010 test, alongside kmemleak: rapido1:/blktests# ./check block/010 ... rapido1:/blktests# echo scan > /sys/kernel/debug/kmemleak [ 306.966708] kmemleak: 32 new suspected memory leaks (see /sys/kernel/debug/kmemleak) rapido1:/blktests# cat /sys/kernel/debug/kmemleak unreferenced object 0xffff88001f86d000 (size 4096): comm "modprobe", pid 231, jiffies 4294892415 (age 318.252s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<ffffffff814b0379>] kmemleak_alloc+0x49/0xa0 [<ffffffff810f180f>] kmem_cache_alloc+0x9f/0xe0 [<ffffffff8124e45f>] badblocks_init+0x2f/0x60 [<ffffffffa0019fae>] 0xffffffffa0019fae [<ffffffffa0021273>] nullb_device_badblocks_store+0x63/0x130 [null_blk] [<ffffffff810004cd>] do_one_initcall+0x3d/0x170 [<ffffffff8109fe0d>] do_init_module+0x56/0x1e9 [<ffffffff8109ebd7>] load_module+0x1c47/0x26a0 [<ffffffff8109f819>] SyS_finit_module+0xa9/0xd0 [<ffffffff814b4f60>] entry_SYSCALL_64_fastpath+0x13/0x94 Fixes: 2f54a613c942 ("nullb: badbblocks support") Signed-off-by: David Disseldorp <ddiss@suse.de> --- drivers/block/null_blk.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)