Revision 2172fa709ab32ca60e86179dc67d0857be8e2c98 authored by Stephen Smalley on 30 January 2014, 16:26:59 UTC, committed by Paul Moore on 05 February 2014, 17:20:51 UTC
Setting an empty security context (length=0) on a file will lead to incorrectly dereferencing the type and other fields of the security context structure, yielding a kernel BUG. As a zero-length security context is never valid, just reject all such security contexts whether coming from userspace via setxattr or coming from the filesystem upon a getxattr request by SELinux. Setting a security context value (empty or otherwise) unknown to SELinux in the first place is only possible for a root process (CAP_MAC_ADMIN), and, if running SELinux in enforcing mode, only if the corresponding SELinux mac_admin permission is also granted to the domain by policy. In Fedora policies, this is only allowed for specific domains such as livecd for setting down security contexts that are not defined in the build host policy. Reproducer: su setenforce 0 touch foo setfattr -n security.selinux foo Caveat: Relabeling or removing foo after doing the above may not be possible without booting with SELinux disabled. Any subsequent access to foo after doing the above will also trigger the BUG. BUG output from Matthew Thode: [ 473.893141] ------------[ cut here ]------------ [ 473.962110] kernel BUG at security/selinux/ss/services.c:654! [ 473.995314] invalid opcode: 0000 [#6] SMP [ 474.027196] Modules linked in: [ 474.058118] CPU: 0 PID: 8138 Comm: ls Tainted: G D I 3.13.0-grsec #1 [ 474.116637] Hardware name: Supermicro X8ST3/X8ST3, BIOS 2.0 07/29/10 [ 474.149768] task: ffff8805f50cd010 ti: ffff8805f50cd488 task.ti: ffff8805f50cd488 [ 474.183707] RIP: 0010:[<ffffffff814681c7>] [<ffffffff814681c7>] context_struct_compute_av+0xce/0x308 [ 474.219954] RSP: 0018:ffff8805c0ac3c38 EFLAGS: 00010246 [ 474.252253] RAX: 0000000000000000 RBX: ffff8805c0ac3d94 RCX: 0000000000000100 [ 474.287018] RDX: ffff8805e8aac000 RSI: 00000000ffffffff RDI: ffff8805e8aaa000 [ 474.321199] RBP: ffff8805c0ac3cb8 R08: 0000000000000010 R09: 0000000000000006 [ 474.357446] R10: 0000000000000000 R11: ffff8805c567a000 R12: 0000000000000006 [ 474.419191] R13: ffff8805c2b74e88 R14: 00000000000001da R15: 0000000000000000 [ 474.453816] FS: 00007f2e75220800(0000) GS:ffff88061fc00000(0000) knlGS:0000000000000000 [ 474.489254] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 474.522215] CR2: 00007f2e74716090 CR3: 00000005c085e000 CR4: 00000000000207f0 [ 474.556058] Stack: [ 474.584325] ffff8805c0ac3c98 ffffffff811b549b ffff8805c0ac3c98 ffff8805f1190a40 [ 474.618913] ffff8805a6202f08 ffff8805c2b74e88 00068800d0464990 ffff8805e8aac860 [ 474.653955] ffff8805c0ac3cb8 000700068113833a ffff880606c75060 ffff8805c0ac3d94 [ 474.690461] Call Trace: [ 474.723779] [<ffffffff811b549b>] ? lookup_fast+0x1cd/0x22a [ 474.778049] [<ffffffff81468824>] security_compute_av+0xf4/0x20b [ 474.811398] [<ffffffff8196f419>] avc_compute_av+0x2a/0x179 [ 474.843813] [<ffffffff8145727b>] avc_has_perm+0x45/0xf4 [ 474.875694] [<ffffffff81457d0e>] inode_has_perm+0x2a/0x31 [ 474.907370] [<ffffffff81457e76>] selinux_inode_getattr+0x3c/0x3e [ 474.938726] [<ffffffff81455cf6>] security_inode_getattr+0x1b/0x22 [ 474.970036] [<ffffffff811b057d>] vfs_getattr+0x19/0x2d [ 475.000618] [<ffffffff811b05e5>] vfs_fstatat+0x54/0x91 [ 475.030402] [<ffffffff811b063b>] vfs_lstat+0x19/0x1b [ 475.061097] [<ffffffff811b077e>] SyS_newlstat+0x15/0x30 [ 475.094595] [<ffffffff8113c5c1>] ? __audit_syscall_entry+0xa1/0xc3 [ 475.148405] [<ffffffff8197791e>] system_call_fastpath+0x16/0x1b [ 475.179201] Code: 00 48 85 c0 48 89 45 b8 75 02 0f 0b 48 8b 45 a0 48 8b 3d 45 d0 b6 00 8b 40 08 89 c6 ff ce e8 d1 b0 06 00 48 85 c0 49 89 c7 75 02 <0f> 0b 48 8b 45 b8 4c 8b 28 eb 1e 49 8d 7d 08 be 80 01 00 00 e8 [ 475.255884] RIP [<ffffffff814681c7>] context_struct_compute_av+0xce/0x308 [ 475.296120] RSP <ffff8805c0ac3c38> [ 475.328734] ---[ end trace f076482e9d754adc ]--- Reported-by: Matthew Thode <mthode@mthode.org> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com>
1 parent 6a96e15
pata_cmd64x.c
/*
* pata_cmd64x.c - CMD64x PATA for new ATA layer
* (C) 2005 Red Hat Inc
* Alan Cox <alan@lxorguk.ukuu.org.uk>
* (C) 2009-2010 Bartlomiej Zolnierkiewicz
* (C) 2012 MontaVista Software, LLC <source@mvista.com>
*
* Based upon
* linux/drivers/ide/pci/cmd64x.c Version 1.30 Sept 10, 2002
*
* cmd64x.c: Enable interrupts at initialization time on Ultra/PCI machines.
* Note, this driver is not used at all on other systems because
* there the "BIOS" has done all of the following already.
* Due to massive hardware bugs, UltraDMA is only supported
* on the 646U2 and not on the 646U.
*
* Copyright (C) 1998 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 1998 David S. Miller (davem@redhat.com)
*
* Copyright (C) 1999-2002 Andre Hedrick <andre@linux-ide.org>
*
* TODO
* Testing work
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <scsi/scsi_host.h>
#include <linux/libata.h>
#define DRV_NAME "pata_cmd64x"
#define DRV_VERSION "0.2.18"
/*
* CMD64x specific registers definition.
*/
enum {
CFR = 0x50,
CFR_INTR_CH0 = 0x04,
CNTRL = 0x51,
CNTRL_CH0 = 0x04,
CNTRL_CH1 = 0x08,
CMDTIM = 0x52,
ARTTIM0 = 0x53,
DRWTIM0 = 0x54,
ARTTIM1 = 0x55,
DRWTIM1 = 0x56,
ARTTIM23 = 0x57,
ARTTIM23_DIS_RA2 = 0x04,
ARTTIM23_DIS_RA3 = 0x08,
ARTTIM23_INTR_CH1 = 0x10,
DRWTIM2 = 0x58,
BRST = 0x59,
DRWTIM3 = 0x5b,
BMIDECR0 = 0x70,
MRDMODE = 0x71,
MRDMODE_INTR_CH0 = 0x04,
MRDMODE_INTR_CH1 = 0x08,
BMIDESR0 = 0x72,
UDIDETCR0 = 0x73,
DTPR0 = 0x74,
BMIDECR1 = 0x78,
BMIDECSR = 0x79,
UDIDETCR1 = 0x7B,
DTPR1 = 0x7C
};
static int cmd648_cable_detect(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u8 r;
/* Check cable detect bits */
pci_read_config_byte(pdev, BMIDECSR, &r);
if (r & (1 << ap->port_no))
return ATA_CBL_PATA80;
return ATA_CBL_PATA40;
}
/**
* cmd64x_set_timing - set PIO and MWDMA timing
* @ap: ATA interface
* @adev: ATA device
* @mode: mode
*
* Called to do the PIO and MWDMA mode setup.
*/
static void cmd64x_set_timing(struct ata_port *ap, struct ata_device *adev, u8 mode)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
struct ata_timing t;
const unsigned long T = 1000000 / 33;
const u8 setup_data[] = { 0x40, 0x40, 0x40, 0x80, 0x00 };
u8 reg;
/* Port layout is not logical so use a table */
const u8 arttim_port[2][2] = {
{ ARTTIM0, ARTTIM1 },
{ ARTTIM23, ARTTIM23 }
};
const u8 drwtim_port[2][2] = {
{ DRWTIM0, DRWTIM1 },
{ DRWTIM2, DRWTIM3 }
};
int arttim = arttim_port[ap->port_no][adev->devno];
int drwtim = drwtim_port[ap->port_no][adev->devno];
/* ata_timing_compute is smart and will produce timings for MWDMA
that don't violate the drives PIO capabilities. */
if (ata_timing_compute(adev, mode, &t, T, 0) < 0) {
printk(KERN_ERR DRV_NAME ": mode computation failed.\n");
return;
}
if (ap->port_no) {
/* Slave has shared address setup */
struct ata_device *pair = ata_dev_pair(adev);
if (pair) {
struct ata_timing tp;
ata_timing_compute(pair, pair->pio_mode, &tp, T, 0);
ata_timing_merge(&t, &tp, &t, ATA_TIMING_SETUP);
}
}
printk(KERN_DEBUG DRV_NAME ": active %d recovery %d setup %d.\n",
t.active, t.recover, t.setup);
if (t.recover > 16) {
t.active += t.recover - 16;
t.recover = 16;
}
if (t.active > 16)
t.active = 16;
/* Now convert the clocks into values we can actually stuff into
the chip */
if (t.recover == 16)
t.recover = 0;
else if (t.recover > 1)
t.recover--;
else
t.recover = 15;
if (t.setup > 4)
t.setup = 0xC0;
else
t.setup = setup_data[t.setup];
t.active &= 0x0F; /* 0 = 16 */
/* Load setup timing */
pci_read_config_byte(pdev, arttim, ®);
reg &= 0x3F;
reg |= t.setup;
pci_write_config_byte(pdev, arttim, reg);
/* Load active/recovery */
pci_write_config_byte(pdev, drwtim, (t.active << 4) | t.recover);
}
/**
* cmd64x_set_piomode - set initial PIO mode data
* @ap: ATA interface
* @adev: ATA device
*
* Used when configuring the devices ot set the PIO timings. All the
* actual work is done by the PIO/MWDMA setting helper
*/
static void cmd64x_set_piomode(struct ata_port *ap, struct ata_device *adev)
{
cmd64x_set_timing(ap, adev, adev->pio_mode);
}
/**
* cmd64x_set_dmamode - set initial DMA mode data
* @ap: ATA interface
* @adev: ATA device
*
* Called to do the DMA mode setup.
*/
static void cmd64x_set_dmamode(struct ata_port *ap, struct ata_device *adev)
{
static const u8 udma_data[] = {
0x30, 0x20, 0x10, 0x20, 0x10, 0x00
};
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
u8 regU, regD;
int pciU = UDIDETCR0 + 8 * ap->port_no;
int pciD = BMIDESR0 + 8 * ap->port_no;
int shift = 2 * adev->devno;
pci_read_config_byte(pdev, pciD, ®D);
pci_read_config_byte(pdev, pciU, ®U);
/* DMA bits off */
regD &= ~(0x20 << adev->devno);
/* DMA control bits */
regU &= ~(0x30 << shift);
/* DMA timing bits */
regU &= ~(0x05 << adev->devno);
if (adev->dma_mode >= XFER_UDMA_0) {
/* Merge the timing value */
regU |= udma_data[adev->dma_mode - XFER_UDMA_0] << shift;
/* Merge the control bits */
regU |= 1 << adev->devno; /* UDMA on */
if (adev->dma_mode > XFER_UDMA_2) /* 15nS timing */
regU |= 4 << adev->devno;
} else {
regU &= ~ (1 << adev->devno); /* UDMA off */
cmd64x_set_timing(ap, adev, adev->dma_mode);
}
regD |= 0x20 << adev->devno;
pci_write_config_byte(pdev, pciU, regU);
pci_write_config_byte(pdev, pciD, regD);
}
/**
* cmd64x_sff_irq_check - check IDE interrupt
* @ap: ATA interface
*
* Check IDE interrupt in CFR/ARTTIM23 registers.
*/
static bool cmd64x_sff_irq_check(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
int irq_mask = ap->port_no ? ARTTIM23_INTR_CH1 : CFR_INTR_CH0;
int irq_reg = ap->port_no ? ARTTIM23 : CFR;
u8 irq_stat;
/* NOTE: reading the register should clear the interrupt */
pci_read_config_byte(pdev, irq_reg, &irq_stat);
return irq_stat & irq_mask;
}
/**
* cmd64x_sff_irq_clear - clear IDE interrupt
* @ap: ATA interface
*
* Clear IDE interrupt in CFR/ARTTIM23 and DMA status registers.
*/
static void cmd64x_sff_irq_clear(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
int irq_reg = ap->port_no ? ARTTIM23 : CFR;
u8 irq_stat;
ata_bmdma_irq_clear(ap);
/* Reading the register should be enough to clear the interrupt */
pci_read_config_byte(pdev, irq_reg, &irq_stat);
}
/**
* cmd648_sff_irq_check - check IDE interrupt
* @ap: ATA interface
*
* Check IDE interrupt in MRDMODE register.
*/
static bool cmd648_sff_irq_check(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
unsigned long base = pci_resource_start(pdev, 4);
int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
u8 mrdmode = inb(base + 1);
return mrdmode & irq_mask;
}
/**
* cmd648_sff_irq_clear - clear IDE interrupt
* @ap: ATA interface
*
* Clear IDE interrupt in MRDMODE and DMA status registers.
*/
static void cmd648_sff_irq_clear(struct ata_port *ap)
{
struct pci_dev *pdev = to_pci_dev(ap->host->dev);
unsigned long base = pci_resource_start(pdev, 4);
int irq_mask = ap->port_no ? MRDMODE_INTR_CH1 : MRDMODE_INTR_CH0;
u8 mrdmode;
ata_bmdma_irq_clear(ap);
/* Clear this port's interrupt bit (leaving the other port alone) */
mrdmode = inb(base + 1);
mrdmode &= ~(MRDMODE_INTR_CH0 | MRDMODE_INTR_CH1);
outb(mrdmode | irq_mask, base + 1);
}
/**
* cmd646r1_bmdma_stop - DMA stop callback
* @qc: Command in progress
*
* Stub for now while investigating the r1 quirk in the old driver.
*/
static void cmd646r1_bmdma_stop(struct ata_queued_cmd *qc)
{
ata_bmdma_stop(qc);
}
static struct scsi_host_template cmd64x_sht = {
ATA_BMDMA_SHT(DRV_NAME),
};
static const struct ata_port_operations cmd64x_base_ops = {
.inherits = &ata_bmdma_port_ops,
.set_piomode = cmd64x_set_piomode,
.set_dmamode = cmd64x_set_dmamode,
};
static struct ata_port_operations cmd64x_port_ops = {
.inherits = &cmd64x_base_ops,
.sff_irq_check = cmd64x_sff_irq_check,
.sff_irq_clear = cmd64x_sff_irq_clear,
.cable_detect = ata_cable_40wire,
};
static struct ata_port_operations cmd646r1_port_ops = {
.inherits = &cmd64x_base_ops,
.sff_irq_check = cmd64x_sff_irq_check,
.sff_irq_clear = cmd64x_sff_irq_clear,
.bmdma_stop = cmd646r1_bmdma_stop,
.cable_detect = ata_cable_40wire,
};
static struct ata_port_operations cmd646r3_port_ops = {
.inherits = &cmd64x_base_ops,
.sff_irq_check = cmd648_sff_irq_check,
.sff_irq_clear = cmd648_sff_irq_clear,
.cable_detect = ata_cable_40wire,
};
static struct ata_port_operations cmd648_port_ops = {
.inherits = &cmd64x_base_ops,
.sff_irq_check = cmd648_sff_irq_check,
.sff_irq_clear = cmd648_sff_irq_clear,
.cable_detect = cmd648_cable_detect,
};
static void cmd64x_fixup(struct pci_dev *pdev)
{
u8 mrdmode;
pci_write_config_byte(pdev, PCI_LATENCY_TIMER, 64);
pci_read_config_byte(pdev, MRDMODE, &mrdmode);
mrdmode &= ~0x30; /* IRQ set up */
mrdmode |= 0x02; /* Memory read line enable */
pci_write_config_byte(pdev, MRDMODE, mrdmode);
/* PPC specific fixup copied from old driver */
#ifdef CONFIG_PPC
pci_write_config_byte(pdev, UDIDETCR0, 0xF0);
#endif
}
static int cmd64x_init_one(struct pci_dev *pdev, const struct pci_device_id *id)
{
static const struct ata_port_info cmd_info[7] = {
{ /* CMD 643 - no UDMA */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.port_ops = &cmd64x_port_ops
},
{ /* CMD 646 with broken UDMA */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.port_ops = &cmd64x_port_ops
},
{ /* CMD 646U with broken UDMA */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.port_ops = &cmd646r3_port_ops
},
{ /* CMD 646U2 with working UDMA */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.udma_mask = ATA_UDMA2,
.port_ops = &cmd646r3_port_ops
},
{ /* CMD 646 rev 1 */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.port_ops = &cmd646r1_port_ops
},
{ /* CMD 648 */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.udma_mask = ATA_UDMA4,
.port_ops = &cmd648_port_ops
},
{ /* CMD 649 */
.flags = ATA_FLAG_SLAVE_POSS,
.pio_mask = ATA_PIO4,
.mwdma_mask = ATA_MWDMA2,
.udma_mask = ATA_UDMA5,
.port_ops = &cmd648_port_ops
}
};
const struct ata_port_info *ppi[] = {
&cmd_info[id->driver_data],
&cmd_info[id->driver_data],
NULL
};
u8 reg;
int rc;
struct pci_dev *bridge = pdev->bus->self;
/* mobility split bridges don't report enabled ports correctly */
int port_ok = !(bridge && bridge->vendor ==
PCI_VENDOR_ID_MOBILITY_ELECTRONICS);
/* all (with exceptions below) apart from 643 have CNTRL_CH0 bit */
int cntrl_ch0_ok = (id->driver_data != 0);
rc = pcim_enable_device(pdev);
if (rc)
return rc;
if (id->driver_data == 0) /* 643 */
ata_pci_bmdma_clear_simplex(pdev);
if (pdev->device == PCI_DEVICE_ID_CMD_646)
switch (pdev->revision) {
/* UDMA works since rev 5 */
default:
ppi[0] = &cmd_info[3];
ppi[1] = &cmd_info[3];
break;
/* Interrupts in MRDMODE since rev 3 */
case 3:
case 4:
ppi[0] = &cmd_info[2];
ppi[1] = &cmd_info[2];
break;
/* Rev 1 with other problems? */
case 1:
ppi[0] = &cmd_info[4];
ppi[1] = &cmd_info[4];
/* FALL THRU */
/* Early revs have no CNTRL_CH0 */
case 2:
case 0:
cntrl_ch0_ok = 0;
break;
}
cmd64x_fixup(pdev);
/* check for enabled ports */
pci_read_config_byte(pdev, CNTRL, ®);
if (!port_ok)
dev_notice(&pdev->dev, "Mobility Bridge detected, ignoring CNTRL port enable/disable\n");
if (port_ok && cntrl_ch0_ok && !(reg & CNTRL_CH0)) {
dev_notice(&pdev->dev, "Primary port is disabled\n");
ppi[0] = &ata_dummy_port_info;
}
if (port_ok && !(reg & CNTRL_CH1)) {
dev_notice(&pdev->dev, "Secondary port is disabled\n");
ppi[1] = &ata_dummy_port_info;
}
return ata_pci_bmdma_init_one(pdev, ppi, &cmd64x_sht, NULL, 0);
}
#ifdef CONFIG_PM
static int cmd64x_reinit_one(struct pci_dev *pdev)
{
struct ata_host *host = pci_get_drvdata(pdev);
int rc;
rc = ata_pci_device_do_resume(pdev);
if (rc)
return rc;
cmd64x_fixup(pdev);
ata_host_resume(host);
return 0;
}
#endif
static const struct pci_device_id cmd64x[] = {
{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_643), 0 },
{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_646), 1 },
{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_648), 5 },
{ PCI_VDEVICE(CMD, PCI_DEVICE_ID_CMD_649), 6 },
{ },
};
static struct pci_driver cmd64x_pci_driver = {
.name = DRV_NAME,
.id_table = cmd64x,
.probe = cmd64x_init_one,
.remove = ata_pci_remove_one,
#ifdef CONFIG_PM
.suspend = ata_pci_device_suspend,
.resume = cmd64x_reinit_one,
#endif
};
module_pci_driver(cmd64x_pci_driver);
MODULE_AUTHOR("Alan Cox");
MODULE_DESCRIPTION("low-level driver for CMD64x series PATA controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, cmd64x);
MODULE_VERSION(DRV_VERSION);
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