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| author | Dmitry Kasatkin <dmitry.kasatkin@intel.com> | 2013-01-18 23:56:39 +0200 |
|---|---|---|
| committer | James Morris <james.l.morris@oracle.com> | 2013-01-22 00:27:50 +1100 |
| commit | a67adb997419fb53540d4a4f79c6471c60bc69b6 (patch) | |
| tree | 5796039c0789a8504fb3b7d1a5cb81b4e47121fb /security | |
| parent | 9a9284153d965a57edc7162a8e57c14c97f3a935 (diff) | |
| download | linux-a67adb997419fb53540d4a4f79c6471c60bc69b6.tar.gz linux-a67adb997419fb53540d4a4f79c6471c60bc69b6.tar.bz2 linux-a67adb997419fb53540d4a4f79c6471c60bc69b6.zip | |
evm: checking if removexattr is not a NULL
The following lines of code produce a kernel oops.
fd = socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
fchmod(fd, 0666);
[ 139.922364] BUG: unable to handle kernel NULL pointer dereference at (null)
[ 139.924982] IP: [< (null)>] (null)
[ 139.924982] *pde = 00000000
[ 139.924982] Oops: 0000 [#5] SMP
[ 139.924982] Modules linked in: fuse dm_crypt dm_mod i2c_piix4 serio_raw evdev binfmt_misc button
[ 139.924982] Pid: 3070, comm: acpid Tainted: G D 3.8.0-rc2-kds+ #465 Bochs Bochs
[ 139.924982] EIP: 0060:[<00000000>] EFLAGS: 00010246 CPU: 0
[ 139.924982] EIP is at 0x0
[ 139.924982] EAX: cf5ef000 EBX: cf5ef000 ECX: c143d600 EDX: c15225f2
[ 139.924982] ESI: cf4d2a1c EDI: cf4d2a1c EBP: cc02df10 ESP: cc02dee4
[ 139.924982] DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[ 139.924982] CR0: 80050033 CR2: 00000000 CR3: 0c059000 CR4: 000006d0
[ 139.924982] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 139.924982] DR6: ffff0ff0 DR7: 00000400
[ 139.924982] Process acpid (pid: 3070, ti=cc02c000 task=d7705340 task.ti=cc02c000)
[ 139.924982] Stack:
[ 139.924982] c1203c88 00000000 cc02def4 cf4d2a1c ae21eefa 471b60d5 1083c1ba c26a5940
[ 139.924982] e891fb5e 00000041 00000004 cc02df1c c1203964 00000000 cc02df4c c10e20c3
[ 139.924982] 00000002 00000000 00000000 22222222 c1ff2222 cf5ef000 00000000 d76efb08
[ 139.924982] Call Trace:
[ 139.924982] [<c1203c88>] ? evm_update_evmxattr+0x5b/0x62
[ 139.924982] [<c1203964>] evm_inode_post_setattr+0x22/0x26
[ 139.924982] [<c10e20c3>] notify_change+0x25f/0x281
[ 139.924982] [<c10cbf56>] chmod_common+0x59/0x76
[ 139.924982] [<c10e27a1>] ? put_unused_fd+0x33/0x33
[ 139.924982] [<c10cca09>] sys_fchmod+0x39/0x5c
[ 139.924982] [<c13f4f30>] syscall_call+0x7/0xb
[ 139.924982] Code: Bad EIP value.
This happens because sockets do not define the removexattr operation.
Before removing the xattr, verify the removexattr function pointer is
not NULL.
Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
Diffstat (limited to 'security')
| -rw-r--r-- | security/integrity/evm/evm_crypto.c | 4 |
1 files changed, 2 insertions, 2 deletions
diff --git a/security/integrity/evm/evm_crypto.c b/security/integrity/evm/evm_crypto.c index dfb26918699c..7dd538ef5b83 100644 --- a/security/integrity/evm/evm_crypto.c +++ b/security/integrity/evm/evm_crypto.c @@ -205,9 +205,9 @@ int evm_update_evmxattr(struct dentry *dentry, const char *xattr_name, rc = __vfs_setxattr_noperm(dentry, XATTR_NAME_EVM, &xattr_data, sizeof(xattr_data), 0); - } - else if (rc == -ENODATA) + } else if (rc == -ENODATA && inode->i_op->removexattr) { rc = inode->i_op->removexattr(dentry, XATTR_NAME_EVM); + } return rc; } |