// For flags

CVE-2024-41050

cachefiles: cyclic allocation of msg_id to avoid reuse

Severity Score

"-"
*CVSS v-

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

Track
*SSVC
Descriptions

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

cachefiles: cyclic allocation of msg_id to avoid reuse

Reusing the msg_id after a maliciously completed reopen request may cause
a read request to remain unprocessed and result in a hung, as shown below:

t1 | t2 | t3
-------------------------------------------------
cachefiles_ondemand_select_req
cachefiles_ondemand_object_is_close(A)
cachefiles_ondemand_set_object_reopening(A)
queue_work(fscache_object_wq, &info->work)
ondemand_object_worker
cachefiles_ondemand_init_object(A)
cachefiles_ondemand_send_req(OPEN)
// get msg_id 6
wait_for_completion(&req_A->done)
cachefiles_ondemand_daemon_read
// read msg_id 6 req_A
cachefiles_ondemand_get_fd
copy_to_user
// Malicious completion msg_id 6
copen 6,-1
cachefiles_ondemand_copen
complete(&req_A->done)
// will not set the object to close
// because ondemand_id && fd is valid.

// ondemand_object_worker() is done
// but the object is still reopening.

// new open req_B
cachefiles_ondemand_init_object(B)
cachefiles_ondemand_send_req(OPEN)
// reuse msg_id 6
process_open_req
copen 6,A.size
// The expected failed copen was executed successfully

Expect copen to fail, and when it does, it closes fd, which sets the
object to close, and then close triggers reopen again. However, due to
msg_id reuse resulting in a successful copen, the anonymous fd is not
closed until the daemon exits. Therefore read requests waiting for reopen
to complete may trigger hung task.

To avoid this issue, allocate the msg_id cyclically to avoid reusing the
msg_id for a very short duration of time.

*Credits: N/A
CVSS Scores
Attack Vector
-
Attack Complexity
-
Privileges Required
-
User Interaction
-
Scope
-
Confidentiality
-
Integrity
-
Availability
-
* Common Vulnerability Scoring System
SSVC
  • Decision:Track
Exploitation
None
Automatable
No
Tech. Impact
Partial
* Organization's Worst-case Scenario
Timeline
  • 2024-07-12 CVE Reserved
  • 2024-07-29 CVE Published
  • 2024-07-30 EPSS Updated
  • 2024-12-19 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.19 < 6.1.100
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.1.100"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.19 < 6.6.41
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.6.41"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.19 < 6.9.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.9.10"
en
Affected
Linux
Search vendor "Linux"
Linux Kernel
Search vendor "Linux" for product "Linux Kernel"
>= 5.19 < 6.10
Search vendor "Linux" for product "Linux Kernel" and version " >= 5.19 < 6.10"
en
Affected