On Wed, 11 Feb 2015, Vladimir Davydov wrote: > Currently, the discard list is only initialized at the beginning of the > function. As a result, if there are > 1 nodes, we can get use-after-free > while processing the second or higher node: > > WARNING: CPU: 60 PID: 1 at lib/list_debug.c:29 __list_add+0x3c/0xa9() > list_add corruption. next->prev should be prev (ffff881ff0a6bb98), but was ffffea007ff57020. (next=ffffea007fbf7320). > Modules linked in: > CPU: 60 PID: 1 Comm: swapper/0 Not tainted 3.19.0-rc7-next-20150203-gb50cadf #2178 > Hardware name: Intel Corporation BRICKLAND/BRICKLAND, BIOS BIVTSDP1.86B.0038.R02.1307231126 07/23/2013 > 0000000000000009 ffff881ff0a6ba88 ffffffff81c2e096 ffffffff810e2d03 > ffff881ff0a6bad8 ffff881ff0a6bac8 ffffffff8108b320 ffff881ff0a6bb18 > ffffffff8154bbc7 ffff881ff0a6bb98 ffffea007fbf7320 ffffea00ffc3c220 > Call Trace: > [<ffffffff81c2e096>] dump_stack+0x4c/0x65 > [<ffffffff810e2d03>] ? console_unlock+0x398/0x3c7 > [<ffffffff8108b320>] warn_slowpath_common+0xa1/0xbb > [<ffffffff8154bbc7>] ? __list_add+0x3c/0xa9 > [<ffffffff8108b380>] warn_slowpath_fmt+0x46/0x48 > [<ffffffff8154bbc7>] __list_add+0x3c/0xa9 > [<ffffffff811bf5aa>] __kmem_cache_shrink+0x12b/0x24c > [<ffffffff81190ca9>] kmem_cache_shrink+0x26/0x38 > [<ffffffff815848b4>] acpi_os_purge_cache+0xe/0x12 > [<ffffffff815c6424>] acpi_purge_cached_objects+0x32/0x7a > [<ffffffff825f70f1>] acpi_initialize_objects+0x17e/0x1ae > [<ffffffff825f5177>] ? acpi_sleep_proc_init+0x2a/0x2a > [<ffffffff825f5209>] acpi_init+0x92/0x25e > [<ffffffff810002bd>] ? do_one_initcall+0x90/0x17f > [<ffffffff811bdfcd>] ? kfree+0x1fc/0x2d5 > [<ffffffff825f5177>] ? acpi_sleep_proc_init+0x2a/0x2a > [<ffffffff8100031a>] do_one_initcall+0xed/0x17f > [<ffffffff825ae0e2>] kernel_init_freeable+0x1f0/0x278 > [<ffffffff81c1f31a>] ? rest_init+0x13e/0x13e > [<ffffffff81c1f328>] kernel_init+0xe/0xda > [<ffffffff81c3ca7c>] ret_from_fork+0x7c/0xb0 > [<ffffffff81c1f31a>] ? rest_init+0x13e/0x13e > > Fix this by initializing the discard list at each iteration of the > for_each_kmem_cache_node loop. Also, move promote lists initialization > to the beginning of the loop to conform. > > fixes: slub-never-fail-to-shrink-cache 8f44a586ac86 ("slub: never fail to shrink cache") > Signed-off-by: Vladimir Davydov <vdavydov@xxxxxxxxxxxxx> > Reported-by: Huang Ying <ying.huang@xxxxxxxxx> > Cc: Christoph Lameter <cl@xxxxxxxxx> > Cc: Pekka Enberg <penberg@xxxxxxxxxx> > Cc: David Rientjes <rientjes@xxxxxxxxxx> > Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Acked-by: David Rientjes <rientjes@xxxxxxxxxx> -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>