From: Jiri Slaby <jslaby@suse.cz>
To: stable@vger.kernel.org
Cc: linux-kernel@vger.kernel.org, Petr Tesarik <ptesarik@suse.cz>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Jiri Slaby <jslaby@suse.cz>
Subject: [PATCH 3.12 03/50] /dev/mem: handle out-of-bounds read/write
Date: Mon, 5 May 2014 14:42:45 +0200 [thread overview]
Message-ID: <3566e03b5bc9c06855b07423ab4c6e2710aa21e4.1399292849.git.jslaby@suse.cz> (raw)
In-Reply-To: <7d4f4737432af6216e86975e587331b9d8b08063.1399292849.git.jslaby@suse.cz>
In-Reply-To: <cover.1399292849.git.jslaby@suse.cz>
From: Petr Tesarik <ptesarik@suse.cz>
3.12-stable review patch. If anyone has any objections, please let me know.
===============
commit 08d2d00b291ed4eb91530050274e67a761c1901d upstream.
The loff_t type may be wider than phys_addr_t (e.g. on 32-bit systems).
Consequently, the file offset may be truncated in the assignment.
Currently, /dev/mem wraps around, which may cause applications to read
or write incorrect regions of memory by accident.
Let's follow POSIX file semantics here and return 0 when reading from
and -EFBIG when writing to an offset that cannot be represented by a
phys_addr_t.
Note that the conditional is optimized out by the compiler if loff_t
has the same size as phys_addr_t.
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
drivers/char/mem.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index f895a8c8a244..d1f4675809f8 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -100,6 +100,9 @@ static ssize_t read_mem(struct file *file, char __user *buf,
ssize_t read, sz;
char *ptr;
+ if (p != *ppos)
+ return 0;
+
if (!valid_phys_addr_range(p, count))
return -EFAULT;
read = 0;
@@ -158,6 +161,9 @@ static ssize_t write_mem(struct file *file, const char __user *buf,
unsigned long copied;
void *ptr;
+ if (p != *ppos)
+ return -EFBIG;
+
if (!valid_phys_addr_range(p, count))
return -EFAULT;
--
1.9.2
next prev parent reply other threads:[~2014-05-05 12:55 UTC|newest]
Thread overview: 52+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-05 12:28 [PATCH 3.12 00/50] 3.12.19-stable review Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 01/50] openvswitch: fix vport-netdev unregister Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 02/50] brcmsmac: fix deadlock on missing firmware Jiri Slaby
2014-05-05 12:42 ` Jiri Slaby [this message]
2014-05-05 12:42 ` [PATCH 3.12 04/50] drivers/net: tulip_remove_one needs to call pci_disable_device() Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 05/50] Bluetooth: Add support for Intel Bluetooth device [8087:0a2a] Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 06/50] iommu/amd: Fix PASID format in INVALIDATE_IOTLB_PAGES command Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 07/50] usbatm: Fix dynamic_debug / ratelimited atm_dbg and atm_rldbg macros Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 08/50] printk: pr_debug_ratelimited: check state first to reduce "callbacks suppressed" messages Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 09/50] dcache: restore error on restart in prepend_path Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 10/50] __dentry_path() fixes Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 11/50] i2c: i801: enable Intel BayTrail SMBUS Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 12/50] e1000e: Fix no connectivity when driver loaded with cable out Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 13/50] ACPI / EC: Process rather than discard events in acpi_ec_clear Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 14/50] ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 15/50] x86/quirks: Add workaround for AMD F16h Erratum792 Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 16/50] amd64_edac: Fix logic to determine channel for F15 M30h processors Jiri Slaby
2014-05-05 12:42 ` [PATCH 3.12 17/50] backing_dev: fix hung task on sync Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 18/50] bdi: avoid oops on device removal Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 19/50] virtio_balloon: don't softlockup on huge balloon changes Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 20/50] ipmi: Fix a race restarting the timer Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 21/50] KVM: ioapic: fix assignment of ioapic->rtc_status.pending_eoi (CVE-2014-0155) Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 22/50] net: ipv4: current group_info should be put after using Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 24/50] powerpc/8xx: mfspr SPRN_TBRx in lieu of mftb/mftbu is not supported Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 25/50] ACPI / sleep: remove panic in case hardware has changed after S4 Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 26/50] user namespace: fix incorrect memory barriers Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 27/50] x86: Adjust irq remapping quirk for older revisions of 5500/5520 chipsets Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 28/50] PCI: designware: Fix RC BAR to be single 64-bit non-prefetchable memory BAR Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 29/50] PCI: designware: Fix iATU programming for cfg1, io and mem viewport Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 30/50] ACPI / button: Add ACPI Button event via netlink routine Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 31/50] staging: comedi: 8255_pci: initialize MITE data window Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 32/50] tty: Set correct tty name in 'active' sysfs attribute Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 33/50] tty: Fix low_latency BUG Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 35/50] Bluetooth: Fix removing Long Term Key Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 36/50] xfs: fix directory hash ordering bug Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 37/50] Btrfs: skip submitting barrier for missing device Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 38/50] Btrfs: fix deadlock with nested trans handles Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 39/50] ext4: fix error return from ext4_ext_handle_uninitialized_extents() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 40/50] ext4: fix partial cluster handling for bigalloc file systems Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 41/50] ext4: fix premature freeing of partial clusters split across leaf blocks Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 42/50] jffs2: Fix segmentation fault found in stress test Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 43/50] jffs2: Fix crash due to truncation of csize Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 44/50] jffs2: avoid soft-lockup in jffs2_reserve_space_gc() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 45/50] jffs2: remove from wait queue after schedule() Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 46/50] sparc32: fix build failure for arch_jump_label_transform Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 47/50] sparc64: don't treat 64-bit syscall return codes as 32-bit Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 48/50] sparc64: Make sure %pil interrupts are enabled during hypervisor yield Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 49/50] wait: fix reparent_leader() vs EXIT_DEAD->EXIT_ZOMBIE race Jiri Slaby
2014-05-05 12:43 ` [PATCH 3.12 50/50] exit: call disassociate_ctty() before exit_task_namespaces() Jiri Slaby
2014-05-05 15:45 ` [PATCH 3.12 00/50] 3.12.19-stable review Guenter Roeck
2014-05-06 14:57 ` Shuah Khan
2014-05-09 8:32 ` Jiri Slaby
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