CVE-2024-40978

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

scsi: qedi: Fix crash while reading debugfs attribute

The qedi_dbg_do_not_recover_cmd_read() function invokes sprintf() directly on a __user pointer, which results into the crash.

To fix this issue, use a small local stack buffer for sprintf() and then call simple_read_from_buffer(), which in turns make the copy_to_user() call.

BUG: unable to handle page fault for address: 00007f4801111000 PGD 8000000864df6067 P4D 8000000864df6067 PUD 864df7067 PMD 846028067 PTE 0 Oops: 0002 [#1] PREEMPT SMP PTI Hardware name: HPE ProLiant DL380 Gen10/ProLiant DL380 Gen10, BIOS U30 06/15/2023 RIP: 0010:memcpy_orig+0xcd/0x130 RSP: 0018:ffffb7a18c3ffc40 EFLAGS: 00010202 RAX: 00007f4801111000 RBX: 00007f4801111000 RCX: 000000000000000f RDX: 000000000000000f RSI: ffffffffc0bfd7a0 RDI: 00007f4801111000 RBP: ffffffffc0bfd7a0 R08: 725f746f6e5f6f64 R09: 3d7265766f636572 R10: ffffb7a18c3ffd08 R11: 0000000000000000 R12: 00007f4881110fff R13: 000000007fffffff R14: ffffb7a18c3ffca0 R15: ffffffffc0bfd7af FS: 00007f480118a740(0000) GS:ffff98e38af00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4801111000 CR3: 0000000864b8e001 CR4: 00000000007706e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: ? __die_body+0x1a/0x60 ? page_fault_oops+0x183/0x510 ? exc_page_fault+0x69/0x150 ? asm_exc_page_fault+0x22/0x30 ? memcpy_orig+0xcd/0x130 vsnprintf+0x102/0x4c0 sprintf+0x51/0x80 qedi_dbg_do_not_recover_cmd_read+0x2f/0x50 [qedi 6bcfdeeecdea037da47069eca2ba717c84a77324] full_proxy_read+0x50/0x80 vfs_read+0xa5/0x2e0 ? folio_add_new_anon_rmap+0x44/0xa0 ? set_pte_at+0x15/0x30 ? do_pte_missing+0x426/0x7f0 ksys_read+0xa5/0xe0 do_syscall_64+0x58/0x80 ? __count_memcg_events+0x46/0x90 ? count_memcg_event_mm+0x3d/0x60 ? handle_mm_fault+0x196/0x2f0 ? do_user_addr_fault+0x267/0x890 ? exc_page_fault+0x69/0x150 entry_SYSCALL_64_after_hwframe+0x72/0xdc RIP: 0033:0x7f4800f20b4d

Weakness

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

Affected Software

Potential Mitigations

• Assume all input is malicious. Use an “accept known good” input validation strategy, i.e., use a list of acceptable inputs that strictly conform to specifications. Reject any input that does not strictly conform to specifications, or transform it into something that does.
• When performing input validation, consider all potentially relevant properties, including length, type of input, the full range of acceptable values, missing or extra inputs, syntax, consistency across related fields, and conformance to business rules. As an example of business rule logic, “boat” may be syntactically valid because it only contains alphanumeric characters, but it is not valid if the input is only expected to contain colors such as “red” or “blue.”
• Do not rely exclusively on looking for malicious or malformed inputs. This is likely to miss at least one undesirable input, especially if the code’s environment changes. This can give attackers enough room to bypass the intended validation. However, denylists can be useful for detecting potential attacks or determining which inputs are so malformed that they should be rejected outright.
• To reduce the likelihood of introducing an out-of-bounds read, ensure that you validate and ensure correct calculations for any length argument, buffer size calculation, or offset. Be especially careful of relying on a sentinel (i.e. special character such as NUL) in untrusted inputs.

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/540.html

References

• https://git.kernel.org/stable/c/144d76a676b630e321556965011b00e2de0b40a7
• https://git.kernel.org/stable/c/21c963de2e86e88f6a8ca556bcebb8e62ab8e901
• https://git.kernel.org/stable/c/28027ec8e32ecbadcd67623edb290dad61e735b5
• https://git.kernel.org/stable/c/397a8990c377ee4b61d6df768e61dff9e316d46b
• https://git.kernel.org/stable/c/56bec63a7fc87ad50b3373a87517dc9770eef9e0
• https://git.kernel.org/stable/c/e2f433ea7d0ff77998766a088a287337fb43ad75
• https://git.kernel.org/stable/c/eaddb86637669f6bad89245ee63f8fb2bfb50241
• https://git.kernel.org/stable/c/fa85b016a56b9775a3fe41e5d26e666945963b46
• https://git.kernel.org/stable/c/144d76a676b630e321556965011b00e2de0b40a7
• https://git.kernel.org/stable/c/21c963de2e86e88f6a8ca556bcebb8e62ab8e901
• https://git.kernel.org/stable/c/28027ec8e32ecbadcd67623edb290dad61e735b5
• https://git.kernel.org/stable/c/397a8990c377ee4b61d6df768e61dff9e316d46b
• https://git.kernel.org/stable/c/56bec63a7fc87ad50b3373a87517dc9770eef9e0
• https://git.kernel.org/stable/c/e2f433ea7d0ff77998766a088a287337fb43ad75
• https://git.kernel.org/stable/c/eaddb86637669f6bad89245ee63f8fb2bfb50241
• https://git.kernel.org/stable/c/fa85b016a56b9775a3fe41e5d26e666945963b46