diff options
| author | Andrey Mirkin <amirkin@openvz.org> | 2006-12-06 20:31:35 -0800 |
|---|---|---|
| committer | Chris Wright <chrisw@sous-sol.org> | 2006-12-16 16:20:48 -0800 |
| commit | 80dc4d3acce8103ad87e14ca8ae6b10a2785c5e5 (patch) | |
| tree | 6ae7b2901aab6b4b4b264f98e6c745900a6503d2 | |
| parent | 26e6a249a64f9bdf4d8553d8ccc5cc3680e53c07 (diff) | |
[PATCH] skip data conversion in compat_sys_mount when data_page is NULL
OpenVZ Linux kernel team has found a problem with mounting in compat mode.
Simple command "mount -t smbfs ..." on Fedora Core 5 distro in 32-bit mode
leads to oops:
Unable to handle kernel NULL pointer dereference at 0000000000000000 RIP:
[<ffffffff802bc7c6>] compat_sys_mount+0xd6/0x290
PGD 34d48067 PUD 34d03067 PMD 0
Oops: 0000 [1] SMP
CPU: 0
Modules linked in: iptable_nat simfs smbfs ip_nat ip_conntrack vzdquota
parport_pc lp parport 8021q bridge llc vznetdev vzmon nfs lockd sunrpc vzdev
iptable_filter af_packet xt_length ipt_ttl xt_tcpmss ipt_TCPMSS
iptable_mangle xt_limit ipt_tos ipt_REJECT ip_tables x_tables thermal
processor fan button battery asus_acpi ac uhci_hcd ehci_hcd usbcore i2c_i801
i2c_core e100 mii floppy ide_cd cdrom
Pid: 14656, comm: mount
RIP: 0060:[<ffffffff802bc7c6>] [<ffffffff802bc7c6>]
compat_sys_mount+0xd6/0x290
RSP: 0000:ffff810034d31f38 EFLAGS: 00010292
RAX: 000000000000002c RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff810034c86bc0 RSI: 0000000000000096 RDI: ffffffff8061fc90
RBP: ffff810034d31f78 R08: 0000000000000000 R09: 000000000000000d
R10: ffff810034d31e58 R11: 0000000000000001 R12: ffff810039dc3000
R13: 000000000805ea48 R14: 0000000000000000 R15: 00000000c0ed0000
FS: 0000000000000000(0000) GS:ffffffff80749000(0033) knlGS:00000000b7d556b0
CS: 0060 DS: 007b ES: 007b CR0: 000000008005003b
CR2: 0000000000000000 CR3: 0000000034d43000 CR4: 00000000000006e0
Process mount (pid: 14656, veid=300, threadinfo ffff810034d30000, task
ffff810034c86bc0)
Stack: 0000000000000000 ffff810034dd0000 ffff810034e4a000 000000000805ea48
0000000000000000 0000000000000000 0000000000000000 0000000000000000
000000000805ea48 ffffffff8021e64e 0000000000000000 0000000000000000
Call Trace:
[<ffffffff8021e64e>] ia32_sysret+0x0/0xa
Code: 83 3b 06 0f 85 41 01 00 00 0f b7 43 0c 89 43 14 0f b7 43 0a
RIP [<ffffffff802bc7c6>] compat_sys_mount+0xd6/0x290
RSP <ffff810034d31f38>
CR2: 0000000000000000
The problem is that data_page pointer can be NULL, so we should skip data
conversion in this case.
Signed-off-by: Andrey Mirkin <amirkin@openvz.org>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
| -rw-r--r-- | fs/compat.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/compat.c b/fs/compat.c index e31e9cf9664..f8c52135782 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -873,7 +873,7 @@ asmlinkage long compat_sys_mount(char __user * dev_name, char __user * dir_name, retval = -EINVAL; - if (type_page) { + if (type_page && data_page) { if (!strcmp((char *)type_page, SMBFS_NAME)) { do_smb_super_data_conv((void *)data_page); } else if (!strcmp((char *)type_page, NCPFS_NAME)) { |