From b9da898b05859ac4a0ea4460d798b6bb655790f3 Mon Sep 17 00:00:00 2001 From: Chao Yu Date: Fri, 15 May 2015 11:14:34 +0800 Subject: [PATCH] f2fs crypto: fix incorrect release for crypto ctx When encryption feature is enable, if we rmmod f2fs module, we will encounter a stack backtrace reported in syslog: "BUG: Bad page state in process rmmod pfn:aaf8a page:f0f4f148 count:0 mapcount:129 mapping:ee2f4104 index:0x80 flags: 0xee2830a4(referenced|lru|slab|private_2|writeback|swapbacked|mlocked) page dumped because: PAGE_FLAGS_CHECK_AT_FREE flag(s) set bad because of flags: flags: 0x2030a0(lru|slab|private_2|writeback|mlocked) Modules linked in: f2fs(O-) fuse bnep rfcomm bluetooth dm_crypt binfmt_misc snd_intel8x0 snd_ac97_codec ac97_bus snd_pcm snd_seq_midi snd_rawmidi snd_seq_midi_event snd_seq snd_timer snd_seq_device joydev ppdev mac_hid lp hid_generic i2c_piix4 parport_pc psmouse snd serio_raw parport soundcore ext4 jbd2 mbcache usbhid hid e1000 [last unloaded: f2fs] CPU: 1 PID: 3049 Comm: rmmod Tainted: G B O 4.1.0-rc3+ #10 Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 00000000 00000000 c0021eb4 c15b7518 f0f4f148 c0021ed8 c112e0b7 c1779174 c9b75674 000aaf8a 01b13ce1 c17791a4 f0f4f148 ee2830a4 c0021ef8 c112e3c3 00000000 f0f4f148 c0021f34 f0f4f148 ee2830a4 ef9f0000 c0021f20 c112fdf8 Call Trace: [] dump_stack+0x41/0x52 [] bad_page.part.72+0xa7/0x100 [] free_pages_prepare+0x213/0x220 [] free_hot_cold_page+0x28/0x120 [] ? try_to_wake_up+0x2b0/0x2b0 [] __free_pages+0x25/0x30 [] mempool_free_pages+0xd/0x10 [] mempool_free+0x31/0x90 [] f2fs_exit_crypto+0x6f/0xf0 [f2fs] [] exit_f2fs_fs+0x23/0x95f [f2fs] [] SyS_delete_module+0x130/0x180 [] ? vm_munmap+0x46/0x60 [] sysenter_do_call+0x12/0x12" The reason is that: since commit 0827e645fd35 ("f2fs crypto: shrink size of the f2fs_crypto_ctx structure") is merged, some fields in f2fs_crypto_ctx structure are merged into a union as they will never be used simultaneously in write path, read path or on free list. In f2fs_exit_crypto, we traverse each crypto ctx from free list, in this moment, our free_list field in union is valid, but still we will try to release memory space which is pointed by other invalid field in union structure for each ctx. Then the error occurs, let's fix it with this patch. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim --- fs/f2fs/crypto.c | 8 -------- 1 file changed, 8 deletions(-) diff --git a/fs/f2fs/crypto.c b/fs/f2fs/crypto.c index 6d38da11918d..7f1ee9e8fc70 100644 --- a/fs/f2fs/crypto.c +++ b/fs/f2fs/crypto.c @@ -233,14 +233,6 @@ void f2fs_exit_crypto(void) struct f2fs_crypto_ctx *pos, *n; list_for_each_entry_safe(pos, n, &f2fs_free_crypto_ctxs, free_list) { - if (pos->w.bounce_page) { - if (pos->flags & - F2FS_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) - __free_page(pos->w.bounce_page); - else - mempool_free(pos->w.bounce_page, - f2fs_bounce_page_pool); - } if (pos->tfm) crypto_free_tfm(pos->tfm); kmem_cache_free(f2fs_crypto_ctx_cachep, pos); -- 2.20.1