CVE-2024-46766

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

ice: move netif_queue_set_napi to rtnl-protected sections

Currently, netif_queue_set_napi() is called from ice_vsi_rebuild() that is not rtnl-locked when called from the reset. This creates the need to take the rtnl_lock just for a single function and complicates the synchronization with .ndo_bpf. At the same time, there no actual need to fill napi-to-queue information at this exact point.

Fill napi-to-queue information when opening the VSI and clear it when the VSI is being closed. Those routines are already rtnl-locked.

Also, rewrite napi-to-queue assignment in a way that prevents inclusion of XDP queues, as this leads to out-of-bounds writes, such as one below.

[ +0.000004] BUG: KASAN: slab-out-of-bounds in netif_queue_set_napi+0x1c2/0x1e0 [ +0.000012] Write of size 8 at addr ffff889881727c80 by task bash/7047 [ +0.000006] CPU: 24 PID: 7047 Comm: bash Not tainted 6.10.0-rc2+ #2 [ +0.000004] Hardware name: Intel Corporation S2600WFT/S2600WFT, BIOS SE5C620.86B.02.01.0014.082620210524 08/26/2021 [ +0.000003] Call Trace: [ +0.000003] [ +0.000002] dump_stack_lvl+0x60/0x80 [ +0.000007] print_report+0xce/0x630 [ +0.000007] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ +0.000007] ? __virt_addr_valid+0x1c9/0x2c0 [ +0.000005] ? netif_queue_set_napi+0x1c2/0x1e0 [ +0.000003] kasan_report+0xe9/0x120 [ +0.000004] ? netif_queue_set_napi+0x1c2/0x1e0 [ +0.000004] netif_queue_set_napi+0x1c2/0x1e0 [ +0.000005] ice_vsi_close+0x161/0x670 [ice] [ +0.000114] ice_dis_vsi+0x22f/0x270 [ice] [ +0.000095] ice_pf_dis_all_vsi.constprop.0+0xae/0x1c0 [ice] [ +0.000086] ice_prepare_for_reset+0x299/0x750 [ice] [ +0.000087] pci_dev_save_and_disable+0x82/0xd0 [ +0.000006] pci_reset_function+0x12d/0x230 [ +0.000004] reset_store+0xa0/0x100 [ +0.000006] ? __pfx_reset_store+0x10/0x10 [ +0.000002] ? __pfx_mutex_lock+0x10/0x10 [ +0.000004] ? __check_object_size+0x4c1/0x640 [ +0.000007] kernfs_fop_write_iter+0x30b/0x4a0 [ +0.000006] vfs_write+0x5d6/0xdf0 [ +0.000005] ? fd_install+0x180/0x350 [ +0.000005] ? __pfx_vfs_write+0x10/0xA10 [ +0.000004] ? do_fcntl+0x52c/0xcd0 [ +0.000004] ? kasan_save_track+0x13/0x60 [ +0.000003] ? kasan_save_free_info+0x37/0x60 [ +0.000006] ksys_write+0xfa/0x1d0 [ +0.000003] ? __pfx_ksys_write+0x10/0x10 [ +0.000002] ? __x64_sys_fcntl+0x121/0x180 [ +0.000004] ? _raw_spin_lock+0x87/0xe0 [ +0.000005] do_syscall_64+0x80/0x170 [ +0.000007] ? _raw_spin_lock+0x87/0xe0 [ +0.000004] ? __pfx__raw_spin_lock+0x10/0x10 [ +0.000003] ? file_close_fd_locked+0x167/0x230 [ +0.000005] ? syscall_exit_to_user_mode+0x7d/0x220 [ +0.000005] ? do_syscall_64+0x8c/0x170 [ +0.000004] ? do_syscall_64+0x8c/0x170 [ +0.000003] ? do_syscall_64+0x8c/0x170 [ +0.000003] ? fput+0x1a/0x2c0 [ +0.000004] ? filp_close+0x19/0x30 [ +0.000004] ? do_dup2+0x25a/0x4c0 [ +0.000004] ? __x64_sys_dup2+0x6e/0x2e0 [ +0.000002] ? syscall_exit_to_user_mode+0x7d/0x220 [ +0.000004] ? do_syscall_64+0x8c/0x170 [ +0.000003] ? __count_memcg_events+0x113/0x380 [ +0.000005] ? handle_mm_fault+0x136/0x820 [ +0.000005] ? do_user_addr_fault+0x444/0xa80 [ +0.000004] ? clear_bhb_loop+0x25/0x80 [ +0.000004] ? clear_bhb_loop+0x25/0x80 [ +0.000002] entry_SYSCALL_64_after_hwframe+0x76/0x7e [ +0.000005] RIP: 0033:0x7f2033593154

Weakness

The product writes data past the end, or before the beginning, of the intended buffer.

Affected Software

Potential Mitigations

• Use a language that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• For example, many languages that perform their own memory management, such as Java and Perl, are not subject to buffer overflows. Other languages, such as Ada and C#, typically provide overflow protection, but the protection can be disabled by the programmer.

• Be wary that a language’s interface to native code may still be subject to overflows, even if the language itself is theoretically safe.

• Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.

• Examples include the Safe C String Library (SafeStr) by Messier and Viega [REF-57], and the Strsafe.h library from Microsoft [REF-56]. These libraries provide safer versions of overflow-prone string-handling functions.

• Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking.

• D3-SFCV (Stack Frame Canary Validation) from D3FEND [REF-1334] discusses canary-based detection in detail.

• Consider adhering to the following rules when allocating and managing an application’s memory:

• Run or compile the software using features or extensions that randomly arrange the positions of a program’s executable and libraries in memory. Because this makes the addresses unpredictable, it can prevent an attacker from reliably jumping to exploitable code.

• Examples include Address Space Layout Randomization (ASLR) [REF-58] [REF-60] and Position-Independent Executables (PIE) [REF-64]. Imported modules may be similarly realigned if their default memory addresses conflict with other modules, in a process known as “rebasing” (for Windows) and “prelinking” (for Linux) [REF-1332] using randomly generated addresses. ASLR for libraries cannot be used in conjunction with prelink since it would require relocating the libraries at run-time, defeating the whole purpose of prelinking.

• For more information on these techniques see D3-SAOR (Segment Address Offset Randomization) from D3FEND [REF-1335].

• Use a CPU and operating system that offers Data Execution Protection (using hardware NX or XD bits) or the equivalent techniques that simulate this feature in software, such as PaX [REF-60] [REF-61]. These techniques ensure that any instruction executed is exclusively at a memory address that is part of the code segment.

• For more information on these techniques see D3-PSEP (Process Segment Execution Prevention) from D3FEND [REF-1336].

References

• https://git.kernel.org/stable/c/2285c2faef19ee08a6bd6754f4c3ec07dceb2889
• https://git.kernel.org/stable/c/2a5dc090b92cfa5270e20056074241c6db5c9cdd