In the Linux kernel, the following vulnerability has been resolved:
igc: Reinstate IGC_REMOVED logic and implement it properly
The initially merged version of the igc driver code (via commit
146740f9abc4, "igc: Add support for PF") contained the following
IGC_REMOVED checks in the igc_rd32/wr32() MMIO accessors:
u32 igc_rd32(struct igc_hw *hw, u32 reg)
{
u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr);
u32 value = 0;
if (IGC_REMOVED(hw_addr))
return ~value;
value = readl(&hw_addr[reg]);
/* reads should not return all F's */
if (!(~value) && (!reg || !(~readl(hw_addr))))
hw->hw_addr = NULL;
return value;
}
And:
#define wr32(reg, val) \
do { \
u8 __iomem *hw_addr = READ_ONCE((hw)->hw_addr); \
if (!IGC_REMOVED(hw_addr)) \
writel((val), &hw_addr[(reg)]); \
} while (0)
E.g. igb has similar checks in its MMIO accessors, and has a similar
macro E1000_REMOVED, which is implemented as follows:
#define E1000_REMOVED(h) unlikely(!(h))
These checks serve to detect and take note of an 0xffffffff MMIO read
return from the device, which can be caused by a PCIe link flap or some
other kind of PCI bus error, and to avoid performing MMIO reads and
writes from that point onwards.
However, the IGC_REMOVED macro was not originally implemented:
#ifndef IGC_REMOVED
#define IGC_REMOVED(a) (0)
#endif /* IGC_REMOVED */
This led to the IGC_REMOVED logic to be removed entirely in a
subsequent commit (commit 3c215fb18e70, "igc: remove IGC_REMOVED
function"), with the rationale that such checks matter only for
virtualization and that igc does not support virtualization -- but a
PCIe device can become detached even without virtualization being in
use, and without proper checks, a PCIe bus error affecting an igc
adapter will lead to various NULL pointer dereferences, as the first
access after the error will set hw->hw_addr to NULL, and subsequent
accesses will blindly dereference this now-NULL pointer.
This patch reinstates the IGC_REMOVED checks in igc_rd32/wr32(), and
implements IGC_REMOVED the way it is done for igb, by checking for the
unlikely() case of hw_addr being NULL. This change prevents the oopses
seen when a PCIe link flap occurs on an igc adapter.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Redhat |
|
No data.
| Package | CPE | Advisory | Released Date |
|---|---|---|---|
| Red Hat Enterprise Linux 8 | |||
| kernel-0:4.18.0-425.3.1.el8 | cpe:/o:redhat:enterprise_linux:8 | RHSA-2022:7683 | 2022-11-08T00:00:00Z |
| Red Hat Enterprise Linux 9 | |||
| kernel-0:5.14.0-162.6.1.el9_1 | cpe:/a:redhat:enterprise_linux:9 | RHSA-2022:8267 | 2022-11-15T00:00:00Z |
| kernel-0:5.14.0-162.6.1.el9_1 | cpe:/o:redhat:enterprise_linux:9 | RHSA-2022:8267 | 2022-11-15T00:00:00Z |
References
History
Sat, 07 Jun 2025 03:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Redhat
Redhat enterprise Linux |
|
| CPEs | cpe:/a:redhat:enterprise_linux:9 cpe:/o:redhat:enterprise_linux:8 cpe:/o:redhat:enterprise_linux:9 |
|
| Vendors & Products |
Redhat
Redhat enterprise Linux |
Thu, 27 Feb 2025 01:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| References |
| |
| Metrics |
threat_severity
|
cvssV3_1
|
Wed, 26 Feb 2025 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | In the Linux kernel, the following vulnerability has been resolved: igc: Reinstate IGC_REMOVED logic and implement it properly The initially merged version of the igc driver code (via commit 146740f9abc4, "igc: Add support for PF") contained the following IGC_REMOVED checks in the igc_rd32/wr32() MMIO accessors: u32 igc_rd32(struct igc_hw *hw, u32 reg) { u8 __iomem *hw_addr = READ_ONCE(hw->hw_addr); u32 value = 0; if (IGC_REMOVED(hw_addr)) return ~value; value = readl(&hw_addr[reg]); /* reads should not return all F's */ if (!(~value) && (!reg || !(~readl(hw_addr)))) hw->hw_addr = NULL; return value; } And: #define wr32(reg, val) \ do { \ u8 __iomem *hw_addr = READ_ONCE((hw)->hw_addr); \ if (!IGC_REMOVED(hw_addr)) \ writel((val), &hw_addr[(reg)]); \ } while (0) E.g. igb has similar checks in its MMIO accessors, and has a similar macro E1000_REMOVED, which is implemented as follows: #define E1000_REMOVED(h) unlikely(!(h)) These checks serve to detect and take note of an 0xffffffff MMIO read return from the device, which can be caused by a PCIe link flap or some other kind of PCI bus error, and to avoid performing MMIO reads and writes from that point onwards. However, the IGC_REMOVED macro was not originally implemented: #ifndef IGC_REMOVED #define IGC_REMOVED(a) (0) #endif /* IGC_REMOVED */ This led to the IGC_REMOVED logic to be removed entirely in a subsequent commit (commit 3c215fb18e70, "igc: remove IGC_REMOVED function"), with the rationale that such checks matter only for virtualization and that igc does not support virtualization -- but a PCIe device can become detached even without virtualization being in use, and without proper checks, a PCIe bus error affecting an igc adapter will lead to various NULL pointer dereferences, as the first access after the error will set hw->hw_addr to NULL, and subsequent accesses will blindly dereference this now-NULL pointer. This patch reinstates the IGC_REMOVED checks in igc_rd32/wr32(), and implements IGC_REMOVED the way it is done for igb, by checking for the unlikely() case of hw_addr being NULL. This change prevents the oopses seen when a PCIe link flap occurs on an igc adapter. | |
| Title | igc: Reinstate IGC_REMOVED logic and implement it properly | |
| References |
|
|
MITRE
Status: PUBLISHED
Assigner: Linux
Published:
Updated: 2025-05-04T08:41:38.201Z
Reserved: 2025-02-26T02:21:30.416Z
Link: CVE-2022-49605
Vulnrichment
No data.
NVD
Status : Received
Published: 2025-02-26T07:01:36.000
Modified: 2025-02-26T07:01:36.000
Link: CVE-2022-49605
Redhat