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From: Greg KH <gregkh@suse.de>
To: linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc: torvalds@linux-foundation.org, akpm@linux-foundation.org,
	alan@lxorguk.ukuu.org.uk,
	"J. Bruce Fields" <bfields@fieldses.org>,
	Neil Brown <neilb@suse.de>,
	linux-nfs@vger.kernel.org, Sasha Levin <levinsasha928@gmail.com>,
	"J. Bruce Fields" <bfields@redhat.com>
Subject: [18/27] nfsd: Fix oops when parsing a 0 length export
Date: Mon, 23 Jan 2012 15:41:04 -0800	[thread overview]
Message-ID: <20120123234203.205581752@clark.kroah.org> (raw)
In-Reply-To: <20120123234224.GA19510@kroah.com>

2.6.32-longterm review patch.  If anyone has any objections, please let me know.

------------------

From: Sasha Levin <levinsasha928@gmail.com>

commit b2ea70afade7080360ac55c4e64ff7a5fafdb67b upstream.

expkey_parse() oopses when handling a 0 length export. This is easily
triggerable from usermode by writing 0 bytes into
'/proc/[proc id]/net/rpc/nfsd.fh/channel'.

Below is the log:

[ 1402.286893] BUG: unable to handle kernel paging request at ffff880077c49fff
[ 1402.287632] IP: [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632] PGD 2206063 PUD 1fdfd067 PMD 1ffbc067 PTE 8000000077c49160
[ 1402.287632] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC
[ 1402.287632] CPU 1
[ 1402.287632] Pid: 20198, comm: trinity Not tainted 3.2.0-rc2-sasha-00058-gc65cd37 #6
[ 1402.287632] RIP: 0010:[<ffffffff812b4b99>]  [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632] RSP: 0018:ffff880077f0fd68  EFLAGS: 00010292
[ 1402.287632] RAX: ffff880077c49fff RBX: 00000000ffffffea RCX: 0000000001043400
[ 1402.287632] RDX: 0000000000000000 RSI: ffff880077c4a000 RDI: ffffffff82283de0
[ 1402.287632] RBP: ffff880077f0fe18 R08: 0000000000000001 R09: ffff880000000000
[ 1402.287632] R10: 0000000000000000 R11: 0000000000000001 R12: ffff880077c4a000
[ 1402.287632] R13: ffffffff82283de0 R14: 0000000001043400 R15: ffffffff82283de0
[ 1402.287632] FS:  00007f25fec3f700(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
[ 1402.287632] CS:  0010 DS: 0000 ES: 0000 CR0: 000000008005003b
[ 1402.287632] CR2: ffff880077c49fff CR3: 0000000077e1d000 CR4: 00000000000406e0
[ 1402.287632] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1402.287632] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
[ 1402.287632] Process trinity (pid: 20198, threadinfo ffff880077f0e000, task ffff880077db17b0)
[ 1402.287632] Stack:
[ 1402.287632]  ffff880077db17b0 ffff880077c4a000 ffff880077f0fdb8 ffffffff810b411e
[ 1402.287632]  ffff880000000000 ffff880077db17b0 ffff880077c4a000 ffffffff82283de0
[ 1402.287632]  0000000001043400 ffffffff82283de0 ffff880077f0fde8 ffffffff81111f63
[ 1402.287632] Call Trace:
[ 1402.287632]  [<ffffffff810b411e>] ? lock_release+0x1af/0x1bc
[ 1402.287632]  [<ffffffff81111f63>] ? might_fault+0x97/0x9e
[ 1402.287632]  [<ffffffff81111f1a>] ? might_fault+0x4e/0x9e
[ 1402.287632]  [<ffffffff81a8bcf2>] cache_do_downcall+0x3e/0x4f
[ 1402.287632]  [<ffffffff81a8c950>] cache_write.clone.16+0xbb/0x130
[ 1402.287632]  [<ffffffff81a8c9df>] ? cache_write_pipefs+0x1a/0x1a
[ 1402.287632]  [<ffffffff81a8c9f8>] cache_write_procfs+0x19/0x1b
[ 1402.287632]  [<ffffffff8118dc54>] proc_reg_write+0x8e/0xad
[ 1402.287632]  [<ffffffff8113fe81>] vfs_write+0xaa/0xfd
[ 1402.287632]  [<ffffffff8114142d>] ? fget_light+0x35/0x9e
[ 1402.287632]  [<ffffffff8113ff8b>] sys_write+0x48/0x6f
[ 1402.287632]  [<ffffffff81bbdb92>] system_call_fastpath+0x16/0x1b
[ 1402.287632] Code: c0 c9 c3 55 48 63 d2 48 89 e5 48 8d 44 32 ff 41 57 41 56 41 55 41 54 53 bb ea ff ff ff 48 81 ec 88 00 00 00 48 89 b5 58 ff ff ff
[ 1402.287632]  38 0a 0f 85 89 02 00 00 c6 00 00 48 8b 3d 44 4a e5 01 48 85
[ 1402.287632] RIP  [<ffffffff812b4b99>] expkey_parse+0x28/0x2e1
[ 1402.287632]  RSP <ffff880077f0fd68>
[ 1402.287632] CR2: ffff880077c49fff
[ 1402.287632] ---[ end trace 368ef53ff773a5e3 ]---

Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: linux-nfs@vger.kernel.org
Signed-off-by: Sasha Levin <levinsasha928@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/nfsd/export.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/fs/nfsd/export.c
+++ b/fs/nfsd/export.c
@@ -106,7 +106,7 @@ static int expkey_parse(struct cache_det
 	struct svc_expkey key;
 	struct svc_expkey *ek = NULL;
 
-	if (mesg[mlen-1] != '\n')
+	if (mlen < 1 || mesg[mlen-1] != '\n')
 		return -EINVAL;
 	mesg[mlen-1] = 0;
 



  parent reply	other threads:[~2012-01-23 23:45 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-01-23 23:42 [00/27] 2.6.32.55-longterm review Greg KH
2012-01-23 23:40 ` [01/27] ext4: fix undefined behavior in ext4_fill_flex_info() Greg KH
2012-01-23 23:40 ` [02/27] ALSA: snd-usb-us122l: Delete calls to preempt_disable Greg KH
2012-01-23 23:40 ` [03/27] ALSA: ice1724 - Check for ac97 to avoid kernel oops Greg KH
2012-01-23 23:40 ` [04/27] ALSA: hda - Return the error from get_wcaps_type() for invalid NIDs Greg KH
2012-01-23 23:40 ` [05/27] HID: bump maximum global item tag report size to 96 bytes Greg KH
2012-01-23 23:40 ` [06/27] UBI: fix use-after-free on error path Greg KH
2012-01-23 23:40 ` [07/27] PCI: Fix PCI_EXP_TYPE_RC_EC value Greg KH
2012-01-23 23:40 ` [08/27] PCI: msi: Disable msi interrupts when we initialize a pci device Greg KH
2012-01-23 23:40 ` [09/27] xen/xenbus: Reject replies with payload > XENSTORE_PAYLOAD_MAX Greg KH
2012-01-23 23:40 ` [10/27] ima: free duplicate measurement memory Greg KH
2012-01-23 23:40 ` [11/27] PNP: work around Dell 1536/1546 BIOS MMCONFIG bug that breaks USB Greg KH
2012-01-23 23:40 ` [12/27] x86: Fix mmap random address range Greg KH
2012-01-23 23:40 ` [13/27] UBI: fix nameless volumes handling Greg KH
2012-01-23 23:41 ` [14/27] i2c: Fix error value returned by several bus drivers Greg KH
2012-01-23 23:41 ` [15/27] [media] V4L/DVB: v4l2-ioctl: integer overflow in video_usercopy() Greg KH
2012-01-23 23:41 ` [16/27] svcrpc: fix double-free on shutdown of nfsd after changing pool mode Greg KH
2012-01-23 23:41 ` [17/27] svcrpc: destroy server sockets all at once Greg KH
2012-01-23 23:41 ` Greg KH [this message]
2012-01-23 23:41 ` [19/27] USB: cdc-wdm: fix misuse of logical operation in place of bitop Greg KH
2012-01-23 23:41 ` [20/27] [S390] fix cputime overflow in uptime_proc_show Greg KH
2012-01-23 23:41 ` [21/27] USB: Fix bad dma problem on WDM device disconnect Greg KH
2012-01-23 23:41 ` [22/27] block: add and use scsi_blk_cmd_ioctl Greg KH
2012-01-23 23:41 ` [23/27] kernel.h: add printk_ratelimited and pr_<level>_rl Greg KH
2012-01-24 14:46   ` Phil Carmody
2012-01-24 16:35     ` Ben Hutchings
2012-01-24 16:43       ` Greg KH
2012-01-23 23:41 ` [24/27] ALSA: HDA: Fix internal microphone on Dell Studio 16 XPS 1645 Greg KH
2012-01-23 23:41 ` [25/27] [SCSI] sym53c8xx: Fix NULL pointer dereference in slave_destroy Greg KH
2012-01-23 23:41 ` [26/27] score: fix off-by-one index into syscall table Greg KH
2012-01-23 23:41 ` [27/27] kprobes: initialize before using a hlist Greg KH

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