From: Wang Hai wanghai38@huawei.com
commit 1aa574312518ef1d60d2dc62d58f7021db3b163a upstream.
When I repeatedly modprobe and rmmod dax.ko, kmemleak report a memory leak as follows:
unreferenced object 0xffff9a5588c05088 (size 8): comm "modprobe", pid 261, jiffies 4294693644 (age 42.063s) ... backtrace: [<00000000e007ced0>] kstrdup+0x35/0x70 [<000000002ae73897>] kstrdup_const+0x3d/0x50 [<000000002b00c9c3>] kvasprintf_const+0xbc/0xf0 [<000000008023282f>] kobject_set_name_vargs+0x3b/0xd0 [<00000000d2cbaa4e>] kobject_set_name+0x62/0x90 [<00000000202e7a22>] bus_register+0x7f/0x2b0 [<000000000b77792c>] 0xffffffffc02840f7 [<000000002d5be5ac>] 0xffffffffc02840b4 [<00000000dcafb7cd>] do_one_initcall+0x58/0x240 [<00000000049fe480>] do_init_module+0x56/0x1e2 [<0000000022671491>] load_module+0x2517/0x2840 [<000000001a2201cb>] __do_sys_finit_module+0x9c/0xe0 [<000000003eb304e7>] do_syscall_64+0x33/0x40 [<0000000051c5fd06>] entry_SYSCALL_64_after_hwframe+0x44/0xa9
When rmmod dax is executed, dax_bus_exit() is missing. This patch can fix this bug.
Fixes: 9567da0b408a ("device-dax: Introduce bus + driver model") Cc: stable@vger.kernel.org Reported-by: Hulk Robot hulkci@huawei.com Signed-off-by: Wang Hai wanghai38@huawei.com Link: https://lore.kernel.org/r/20201201135929.66530-1-wanghai38@huawei.com Signed-off-by: Dan Williams dan.j.williams@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/dax/super.c | 1 + 1 file changed, 1 insertion(+)
--- a/drivers/dax/super.c +++ b/drivers/dax/super.c @@ -752,6 +752,7 @@ err_chrdev:
static void __exit dax_core_exit(void) { + dax_bus_exit(); unregister_chrdev_region(dax_devt, MINORMASK+1); ida_destroy(&dax_minor_ida); dax_fs_exit();