On Fri, Jun 19, 2020 at 04:17:34PM -0700, Jakub Kicinski wrote: > Hi! > > I'm trying to use debugfs_create_u32_array() in drivers/net/netdevsim > and it causes memory leaks: > > unreferenced object 0xffff8880546642a0 (size 16): > comm "test_udp_tuns.s", pid 2146, jiffies 4294928368 (age 3772.435s) > hex dump (first 16 bytes): > 84 52 6a 4d 80 88 ff ff 04 00 00 00 f3 78 7e 89 .RjM.........x~. > backtrace: > [<000000006962a447>] debugfs_create_u32_array+0x3f/0x90 > > I can see that debugfs_create_u32_array() allocates a structure at > create time that ends up assigned to inode->i_private, but I don't > see it freed anywhere. > > Am I missing something? I'm pretty sure files get removed, cause the > driver calls debugfs_remove_recursive() and no other file types leaks.
Yeah, that's a bug, nice catch. The debugfs_create*() functions should not allocate local memory as we can't know to free that memory when the file is removed. Can you fix this up, or do you want me to? I only see one in-kernel user of this, so it shouldn't be that tough to do so. The one user never removes that file so that's why no one noticed this before. thanks, greg k-h
