From 1b8553c04bf95180eb91be94f089a1e8b38cfd62 Mon Sep 17 00:00:00 2001 From: Vegard Nossum Date: Wed, 3 Aug 2016 19:59:47 +0300 Subject: [PATCH] 9p/trans_virtio: use kvfree() for iov_iter_get_pages_alloc() The memory allocated by iov_iter_get_pages_alloc() can be allocated with vmalloc() if kmalloc() failed -- see get_pages_array(). In that case we need to free it with vfree(), so let's use kvfree(). The bug manifests like this: BUG: unable to handle kernel paging request at ffffeb0400072da0 IP: [] kfree+0x4b/0x140 PGD 0 Oops: 0000 [#1] PREEMPT SMP KASAN CPU: 2 PID: 675 Comm: trinity-c2 Not tainted 4.7.0-rc7+ #14 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Ubuntu-1.8.2-1ubuntu1 04/01/2014 task: ffff8800badef2c0 ti: ffff880069208000 task.ti: ffff880069208000 RIP: 0010:[] [] kfree+0x4b/0x140 RSP: 0000:ffff88006920f3f0 EFLAGS: 00010282 RAX: ffffea0000000000 RBX: ffffc90001cb6000 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000246 RDI: ffffc90001cb6000 RBP: ffff88006920f410 R08: 0000000000000000 R09: dffffc0000000000 R10: ffff8800badefa30 R11: 0000056a3d3b0d9f R12: ffff88006920f620 R13: ffffeb0400072d80 R14: ffff8800baa94078 R15: 0000000000000000 FS: 00007fbd2b437700(0000) GS:ffff88011af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffeb0400072da0 CR3: 000000006926d000 CR4: 00000000000006e0 Stack: 0000000000000001 ffff88006920f620 ffffed001755280f ffff8800baa94078 ffff88006920f6a8 ffffffff8310442b dffffc0000000000 ffff8800badefa30 ffff8800badefa28 ffff88011af1fba0 1ffff1000d241e98 ffff8800ba892150 Call Trace: [] p9_virtio_zc_request+0x72b/0xdb0 [] p9_client_zc_rpc.constprop.8+0x246/0xb10 [] p9_client_read+0x4c9/0x750 [] v9fs_fid_readpage+0x14c/0x320 [] v9fs_vfs_readpage+0x36/0x50 [] filemap_fault+0x9a3/0xe60 [] __do_fault+0x158/0x300 [] handle_mm_fault+0x1cf1/0x3c80 [] __do_page_fault+0x30a/0x8e0 [] do_page_fault+0x2f/0x80 [] do_async_page_fault+0x27/0xa0 [] async_page_fault+0x28/0x30 Code: 00 80 41 54 53 49 01 fd 48 0f 42 05 b0 39 67 02 48 89 fb 49 01 c5 48 b8 00 00 00 00 00 ea ff ff 49 c1 ed 0c 49 c1 e5 06 49 01 c5 <49> 8b 45 20 48 8d 50 ff a8 01 4c 0f 45 ea 49 8b 55 20 48 8d 42 RIP [] kfree+0x4b/0x140 RSP CR2: ffffeb0400072da0 ---[ end trace f3d59a04bafec038 ]--- Cc: Al Viro Signed-off-by: Vegard Nossum Signed-off-by: Michael S. Tsirkin --- net/9p/trans_virtio.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/net/9p/trans_virtio.c b/net/9p/trans_virtio.c index 4acb1d5417aa..f24b25c25106 100644 --- a/net/9p/trans_virtio.c +++ b/net/9p/trans_virtio.c @@ -507,8 +507,8 @@ err_out: /* wakeup anybody waiting for slots to pin pages */ wake_up(&vp_wq); } - kfree(in_pages); - kfree(out_pages); + kvfree(in_pages); + kvfree(out_pages); return err; } -- 2.39.5