linux-toradex.git/fs/smbfs, branch v2.6.16.44-rc1

[PATCH] smbfs: Fix slab corruption in samba error path

2006-05-20T22:00:29+00:00

Yesterday, I got the following error with 2.6.16.13 during a file copy from
a smb filesystem over a wireless link.  I guess there was some error on the
wireless link, which in turn caused an error condition for the smb
filesystem.

In the log, smb_file_read reports error=4294966784 (0xfffffe00), which also
shows up in the slab dumps, and also is -ERESTARTSYS.  Error code 27499
corresponds to 0x6b6b, so the rq_errno field seems to be the only one being
set after freeing the slab.

In smb_add_request (which is the only place in smbfs where I found
ERESTARTSYS), I found the following:

        if (!timeleft || signal_pending(current)) {
                /*
                 * On timeout or on interrupt we want to try and remove the
                 * request from the recvq/xmitq.
                 */
                smb_lock_server(server);
                if (!(req->rq_flags & SMB_REQ_RECEIVED)) {
                        list_del_init(&req->rq_queue);
                        smb_rput(req);
                }
                smb_unlock_server(server);
        }
	[...]
        if (signal_pending(current))
                req->rq_errno = -ERESTARTSYS;

I guess that some codepath like smbiod_flush() caused the request to be
removed from the queue, and smb_rput(req) be called, without
SMB_REQ_RECEIVED being set.  This violates an asumption made by the quoted
code.

Then, the above code calls smb_rput(req) again, the req gets freed, and
req->rq_errno = -ERESTARTSYS writes into the already freed slab.  As
list_del_init doesn't cause an error if called multiple times, that does
cause the observed behaviour (freed slab with rq_errno=-ERESTARTSYS).

If this observation is correct, the following patch should fix it.

I wonder why the smb code uses list_del_init everywhere - using list_del
instead would catch such situations by poisoning the next and prev
pointers.

May  4 23:29:21 knautsch kernel: [17180085.456000] ipw2200: Firmware error detected.  Restarting.
May  4 23:29:21 knautsch kernel: [17180085.456000] ipw2200: Sysfs 'error' log captured.
May  4 23:33:02 knautsch kernel: [17180306.316000] ipw2200: Firmware error detected.  Restarting.
May  4 23:33:02 knautsch kernel: [17180306.316000] ipw2200: Sysfs 'error' log already exists.
May  4 23:33:02 knautsch kernel: [17180306.968000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:34:18 knautsch kernel: [17180383.256000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:34:18 knautsch kernel: [17180383.284000] SMB connection re-established (-5)
May  4 23:37:19 knautsch kernel: [17180563.956000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:40:09 knautsch kernel: [17180733.636000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:40:26 knautsch kernel: [17180750.700000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:43:02 knautsch kernel: [17180907.304000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:43:08 knautsch kernel: [17180912.324000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:43:34 knautsch kernel: [17180938.416000] smb_errno: class Unknown, code 27499 from command 0x6b
May  4 23:43:34 knautsch kernel: [17180938.416000] Slab corruption: start=c4ebe09c, len=244
May  4 23:43:34 knautsch kernel: [17180938.416000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:43:34 knautsch kernel: [17180938.416000] Last user: [](smb_rput+0x53/0x90 [smbfs])
May  4 23:43:34 knautsch kernel: [17180938.416000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b
May  4 23:43:34 knautsch kernel: [17180938.416000] 0f0: 00 fe ff ff
May  4 23:43:34 knautsch kernel: [17180938.416000] Next obj: start=c4ebe19c, len=244
May  4 23:43:34 knautsch kernel: [17180938.416000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:43:34 knautsch kernel: [17180938.416000] Last user: [<00000000>](_stext+0x3feffde0/0x30)
May  4 23:43:34 knautsch kernel: [17180938.416000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:43:34 knautsch kernel: [17180938.416000] 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:43:34 knautsch kernel: [17180938.460000] SMB connection re-established (-5)
May  4 23:43:42 knautsch kernel: [17180946.292000] ipw2200: Firmware error detected.  Restarting.
May  4 23:43:42 knautsch kernel: [17180946.292000] ipw2200: Sysfs 'error' log already exists.
May  4 23:45:04 knautsch kernel: [17181028.752000] ipw2200: Firmware error detected.  Restarting.
May  4 23:45:04 knautsch kernel: [17181028.752000] ipw2200: Sysfs 'error' log already exists.
May  4 23:45:05 knautsch kernel: [17181029.868000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:45:36 knautsch kernel: [17181060.984000] smb_errno: class Unknown, code 27499 from command 0x6b
May  4 23:45:36 knautsch kernel: [17181060.984000] Slab corruption: start=c4ebe09c, len=244
May  4 23:45:36 knautsch kernel: [17181060.984000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:45:36 knautsch kernel: [17181060.984000] Last user: [](smb_rput+0x53/0x90 [smbfs])
May  4 23:45:36 knautsch kernel: [17181060.984000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b
May  4 23:45:36 knautsch kernel: [17181060.984000] 0f0: 00 fe ff ff
May  4 23:45:36 knautsch kernel: [17181060.984000] Next obj: start=c4ebe19c, len=244
May  4 23:45:36 knautsch kernel: [17181060.984000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:45:36 knautsch kernel: [17181060.984000] Last user: [<00000000>](_stext+0x3feffde0/0x30)
May  4 23:45:36 knautsch kernel: [17181060.984000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:45:36 knautsch kernel: [17181060.984000] 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:45:36 knautsch kernel: [17181061.024000] SMB connection re-established (-5)
May  4 23:46:17 knautsch kernel: [17181102.132000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:47:46 knautsch kernel: [17181190.468000] smb_errno: class Unknown, code 27499 from command 0x6b
May  4 23:47:46 knautsch kernel: [17181190.468000] Slab corruption: start=c4ebe09c, len=244
May  4 23:47:46 knautsch kernel: [17181190.468000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:47:46 knautsch kernel: [17181190.468000] Last user: [](smb_rput+0x53/0x90 [smbfs])
May  4 23:47:46 knautsch kernel: [17181190.468000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6a 6b 6b 6b 6b 6b 6b 6b
May  4 23:47:46 knautsch kernel: [17181190.468000] 0f0: 00 fe ff ff
May  4 23:47:46 knautsch kernel: [17181190.468000] Next obj: start=c4ebe19c, len=244
May  4 23:47:46 knautsch kernel: [17181190.468000] Redzone: 0x5a2cf071/0x5a2cf071.
May  4 23:47:46 knautsch kernel: [17181190.468000] Last user: [<00000000>](_stext+0x3feffde0/0x30)
May  4 23:47:46 knautsch kernel: [17181190.468000] 000: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:47:46 knautsch kernel: [17181190.468000] 010: 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
May  4 23:47:46 knautsch kernel: [17181190.492000] SMB connection re-established (-5)
May  4 23:49:20 knautsch kernel: [17181284.828000] smb_file_read: //some_file validation failed, error=4294966784
May  4 23:49:39 knautsch kernel: [17181303.896000] smb_file_read: //some_file validation failed, error=4294966784

Signed-off-by: Jan Niehusmann 
Signed-off-by: Andrew Morton 
Signed-off-by: Chris Wright 
Signed-off-by: Greg Kroah-Hartman

[PATCH] smbfs chroot issue (CVE-2006-1864)

2006-05-05T00:03:36+00:00

Mark Moseley reported that a chroot environment on a SMB share can be
left via "cd ..\\".  Similar to CVE-2006-1863 issue with cifs, this fix
is for smbfs.

Steven French  wrote:

Looks fine to me.  This should catch the slash on lookup or equivalent,
which will be all obvious paths of interest.

Signed-off-by: Chris Wright

[PATCH] smbfs readdir vs signal fix

2006-02-01T16:53:09+00:00

An old patch designed to fix http://bugme.osdl.org/show_bug.cgi?id=4497,
"getdents gives empty/random result upon signal".

If smbfs's readdir() is interupted by a signal, smb_readdir() failed to
noticed that and proceeded to treat the unread-into page as valid directory
contents.  Fix that up by handling the -ERESTARTSYS.

Thanks to Stian Skjelstad for reporting and testing.

Cc: Stian Skjelstad 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] smbfs: remove kmalloc wrapper

2006-01-15T02:27:13+00:00

Remove the remaining kmalloc() wrapper bits from fs/smbfs/.

Signed-off-by: Pekka Enberg 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] capable/capability.h (fs/)

2006-01-12T02:42:13+00:00

fs: Use  where capable() is used.

Signed-off-by: Randy Dunlap 
Acked-by: Tim Schmielau 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fs/smbfs/proc.c: fix data corruption in smb_proc_setattr_unix()

2006-01-09T04:14:04+00:00

This patch fixes a data corruption in smb_proc_setattr_unix()
(smb_filetype_from_mode() returns an u32, and there are only four bytes
reserved for it in data.

Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] shrink dentry struct

2006-01-09T04:13:58+00:00

Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.

Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)

This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.

At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.

Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)

As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.

Signed-off-by: Eric Dumazet 
Cc: Dipankar Sarma 
Cc: Maneesh Soni 
Cc: Miklos Szeredi 
Cc: "Paul E. McKenney" 
Cc: Ian Kent 
Cc: Paul Jackson 
Cc: Al Viro 
Cc: Christoph Hellwig 
Cc: Trond Myklebust 
Cc: Neil Brown 
Cc: James Morris 
Cc: Stephen Smalley 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] fix possible PAGE_CACHE_SHIFT overflows

2006-01-09T04:13:54+00:00

We've had two instances recently of overflows when doing

	64_bit_value = (32_bit_value << PAGE_CACHE_SHIFT)

I did a tree-wide grep of `<<.*PAGE_CACHE_SHIFT' and this is the result.

- afs_rxfs_fetch_descriptor.offset is of type off_t, which seems broken.

- jfs and jffs are limited to 4GB anyway.

- reiserfs map_block_for_writepage() takes an unsigned long for the block -
  it should take sector_t.  (It'll fail for huge filesystems with
  blocksizepage_base)

Cc: Oleg Drokin 
Cc: David Howells 
Cc: David Woodhouse 
Cc: 
Cc: Christoph Hellwig 
Cc: Anton Altaparmakov 
Cc: Jeff Dike 
Cc: Paolo 'Blaisorblade' Giarrusso 
Cc: Roman Zippel 
Cc: 
Cc: Miklos Szeredi 
Cc: Russell King 
Cc: Trond Myklebust 
Cc: Neil Brown 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Fix and add EXPORT_SYMBOL(filemap_write_and_wait)

2006-01-09T04:13:47+00:00

This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it.

See mm/filemap.c:

And changes the filemap_write_and_wait() and filemap_write_and_wait_range().

Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite()
returns error.  However, even if filemap_fdatawrite() returned an
error, it may have submitted the partially data pages to the device.
(e.g. in the case of -ENOSPC)


Andrew Morton writes,

If filemap_fdatawrite() returns an error, this might be due to some
I/O problem: dead disk, unplugged cable, etc.  Given the generally
crappy quality of the kernel's handling of such exceptions, there's a
good chance that the filemap_fdatawait() will get stuck in D state
forever.


So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO.

Trond, could you please review the nfs part?  Especially I'm not sure,
nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not.

Acked-by: Trond Myklebust 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] smbfs: 'names_cache' memory leak

2005-11-07T15:53:39+00:00

Data allocated with "__getname()" should always be free'd with "__putname()"
because of the AUDITSYSCALL code.

Signed-off-by: Davi Arnaut 
Cc: Urban Widmark 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds