CVE-2024-26842

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

scsi: ufs: core: Fix shift issue in ufshcd_clear_cmd()

When task_tag >= 32 (in MCQ mode) and sizeof(unsigned int) == 4, 1U « task_tag will out of bounds for a u32 mask. Fix this up to prevent SHIFT_ISSUE (bitwise shifts that are out of bounds for their data type).

[name:debug_monitors&]Unexpected kernel BRK exception at EL1 [name:traps&]Internal error: BRK handler: 00000000f2005514 [#1] PREEMPT SMP [name:mediatek_cpufreq_hw&]cpufreq stop DVFS log done [name:mrdump&]Kernel Offset: 0x1ba5800000 from 0xffffffc008000000 [name:mrdump&]PHYS_OFFSET: 0x80000000 [name:mrdump&]pstate: 22400005 (nzCv daif +PAN -UAO) [name:mrdump&]pc : [0xffffffdbaf52bb2c] ufshcd_clear_cmd+0x280/0x288 [name:mrdump&]lr : [0xffffffdbaf52a774] ufshcd_wait_for_dev_cmd+0x3e4/0x82c [name:mrdump&]sp : ffffffc0081471b0 Workqueue: ufs_eh_wq_0 ufshcd_err_handler Call trace: dump_backtrace+0xf8/0x144 show_stack+0x18/0x24 dump_stack_lvl+0x78/0x9c dump_stack+0x18/0x44 mrdump_common_die+0x254/0x480 [mrdump] ipanic_die+0x20/0x30 [mrdump] notify_die+0x15c/0x204 die+0x10c/0x5f8 arm64_notify_die+0x74/0x13c do_debug_exception+0x164/0x26c el1_dbg+0x64/0x80 el1h_64_sync_handler+0x3c/0x90 el1h_64_sync+0x68/0x6c ufshcd_clear_cmd+0x280/0x288 ufshcd_wait_for_dev_cmd+0x3e4/0x82c ufshcd_exec_dev_cmd+0x5bc/0x9ac ufshcd_verify_dev_init+0x84/0x1c8 ufshcd_probe_hba+0x724/0x1ce0 ufshcd_host_reset_and_restore+0x260/0x574 ufshcd_reset_and_restore+0x138/0xbd0 ufshcd_err_handler+0x1218/0x2f28 process_one_work+0x5fc/0x1140 worker_thread+0x7d8/0xe20 kthread+0x25c/0x468 ret_from_fork+0x10/0x20

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/7ac9e18f5d66087cd22751c5c5bf0090eb0038fe
• https://git.kernel.org/stable/c/a992425d18e5f7c48931121993c6c69426f2a8fb
• https://git.kernel.org/stable/c/b513d30d59bb383a6a5d6b533afcab2cee99a8f8
• https://git.kernel.org/stable/c/7ac9e18f5d66087cd22751c5c5bf0090eb0038fe
• https://git.kernel.org/stable/c/a992425d18e5f7c48931121993c6c69426f2a8fb
• https://git.kernel.org/stable/c/b513d30d59bb383a6a5d6b533afcab2cee99a8f8