CVE-2024-42109 — netfilter: nf_tables: unconditionally flush pending work before notifier

Affected: Linux

In the Linux kernel, the following vulnerability has been resolved:

netfilter: nf_tables: unconditionally flush pending work before notifier

syzbot reports:

KASAN: slab-uaf in nft_ctx_update include/net/netfilter/nf_tables.h:1831 KASAN: slab-uaf in nft_commit_release net/netfilter/nf_tables_api.c:9530 KASAN: slab-uaf int nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597 Read of size 2 at addr ffff88802b0051c4 by task kworker/1:1/45 [..] Workqueue: events nf_tables_trans_destroy_work Call Trace: nft_ctx_update include/net/netfilter/nf_tables.h:1831 [inline] nft_commit_release net/netfilter/nf_tables_api.c:9530 [inline] nf_tables_trans_destroy_work+0x152b/0x1750 net/netfilter/nf_tables_api.c:9597

Problem is that the notifier does a conditional flush, but its possible that the table-to-be-removed is still referenced by transactions being processed by the worker, so we need to flush unconditionally.

We could make the flush_work depend on whether we found a table to delete in nf-next to avoid the flush for most cases.

AFAICS this problem is only exposed in nf-next, with commit e169285f8c56 ("netfilter: nf_tables: do not store nft_ctx in transaction objects"), with this commit applied there is an unconditional fetch of table->family which is whats triggering the above splat.

USN-7007-1 — linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gcp-5.15, linux-gke, linux-gkeop, linux-gkeop-5.15, linux-hwe-5.15,…

Affected: Ubuntu:20.04:LTS: linux-aws-5.15, Ubuntu:20.04:LTS: linux-gcp-5.15, Ubuntu:20.04:LTS: linux-gkeop-5.15, Ubuntu:20.04:LTS: linux-hwe-5.15, Ubuntu:20.04:LTS: linux-intel-iotg-5.15, Ubuntu:22.04:LTS: linux, Ubuntu:22.04:LTS: linux-aws, Ubuntu:22.04:LTS: linux-gcp, Ubuntu:22.04:LTS: linux-gke, Ubuntu:22.04:LTS: linux-gkeop and 6 more

Chenyuan Yang discovered that the CEC driver driver in the Linux kernel contained a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2024-23848)

Chenyuan Yang discovered that the USB Gadget subsystem in the Linux kernel did not properly check for the device to be enabled before writing. A local attacker could possibly use this to cause a denial of service. (CVE-2024-25741)

It was discovered that the JFS file system contained an out-of-bounds read vulnerability when printing xattr debug information. A local attacker could use this to cause a denial of service (system crash). (CVE-2024-40902)

Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system. This update corrects flaws in the following subsystems: - ARM64 architecture; - M68K architecture; - MIPS architecture; - PowerPC architecture; - RISC-V architecture; - x86 architecture; - Block layer subsystem; - Cryptographic API; - Accessibility subsystem; - ACPI drivers; - Serial ATA and Parallel ATA drivers; - Drivers core; - Bluetooth drivers; - Character device driver; - CPU frequency scaling framework; - Hardware crypto device drivers; - Buffer Sharing and Synchronization framework; - DMA engine subsystem; - FPGA Framework; - GPIO subsystem; - GPU drivers; - Greybus drivers; - HID subsystem; - HW tracing; - I2C…

Most recent entries from all

CVE-2024-42109 — netfilter: nf_tables: unconditionally flush pending work before notifier

USN-7007-1 — linux, linux-aws, linux-aws-5.15, linux-gcp, linux-gcp-5.15, linux-gke, linux-gkeop, linux-gkeop-5.15, linux-hwe-5.15,…