afs: Fix oops in afs_unlink_writeback

f129ccc9 · Anton Blanchard <[email protected]> · 2011-02-25 15:33:02 +00:00

I'm seeing the following oops when testing afs:

  Unable to handle kernel paging request for data at address 0x00000008
  ...
  NIP [c0000000003393b0] .afs_unlink_writeback+0x38/0xc0
  LR [c00000000033987c] .afs_put_writeback+0x98/0xec
  Call Trace:
  [c00000000345f600] [c00000000033987c] .afs_put_writeback+0x98/0xec
  [c00000000345f690] [c00000000033ae80] .afs_write_begin+0x6a4/0x75c
  [c00000000345f790] [c00000000012b77c] .generic_file_buffered_write+0x148/0x320
  [c00000000345f8d0] [c00000000012e1b8] .__generic_file_aio_write+0x37c/0x3e4
  [c00000000345f9d0] [c00000000012e2a8] .generic_file_aio_write+0x88/0xfc
  [c00000000345fa90] [c0000000003390a8] .afs_file_write+0x10c/0x178
  [c00000000345fb40] [c000000000188788] .do_sync_write+0xc4/0x128
  [c00000000345fcc0] [c000000000189658] .vfs_write+0xe8/0x1d8
  [c00000000345fd70] [c000000000189884] .SyS_write+0x68/0xb0
  [c00000000345fe30] [c000000000008564] syscall_exit+0x0/0x40

afs_write_begin hits an error and calls afs_unlink_writeback. In there
we do list_del_init on an uninitialised list.

The patch below initialises ->link when creating the afs_writeback struct.

Signed-off-by: Anton Blanchard <[email protected]>
Signed-off-by: David Howells <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>

Commit: f129ccc9231c95513a1227ca9da876beeb03e577
Parents: 4662db44

Changes

1 files changed · +1 −0

File	Status	Add	Del	Content
fs/afs/write.c	modified	+1	−0	View file

fs/afs/write.c

View file

diff --git a/fs/afs/write.c b/fs/afs/write.c
index 15690bb..789b3af 100644
--- a/fs/afs/write.c
+++ b/fs/afs/write.c
@@ -140,6 +140,7 @@ int afs_write_begin(struct file *file, struct address_space *mapping,
 	candidate->first = candidate->last = index;
 	candidate->offset_first = from;
 	candidate->to_last = to;
+	INIT_LIST_HEAD(&candidate->link);
 	candidate->usage = 1;
 	candidate->state = AFS_WBACK_PENDING;
 	init_waitqueue_head(&candidate->waitq);