CVE-2024-49870
Linux Kernel Cachefiles Dentry Leak Vulnerability
Description
In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: <TASK> d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code.
INFO
Published Date :
Oct. 21, 2024, 6:15 p.m.
Last Modified :
Oct. 25, 2024, 12:55 p.m.
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Remotely Exploitable :
No
Impact Score :
3.6
Exploitability Score :
1.8
References to Advisories, Solutions, and Tools
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CVE-2024-49870.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
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The following list is the news that have been mention
CVE-2024-49870 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-49870 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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Initial Analysis by [email protected]
Oct. 25, 2024
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Changed Reference Type https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b No Types Assigned https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b Patch Changed Reference Type https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 No Types Assigned https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 Patch Changed Reference Type https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 No Types Assigned https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 Patch Changed Reference Type https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c No Types Assigned https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c Patch Changed Reference Type https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 No Types Assigned https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 Patch Added CWE NIST CWE-401 Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 5.17 up to (excluding) 6.1.113 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.2 up to (excluding) 6.6.55 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.7 up to (excluding) 6.10.14 *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.11 up to (excluding) 6.11.3 *cpe:2.3:o:linux:linux_kernel:6.12:rc1:*:*:*:*:*:* -
CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Oct. 21, 2024
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: cachefiles: fix dentry leak in cachefiles_open_file() A dentry leak may be caused when a lookup cookie and a cull are concurrent: P1 | P2 ----------------------------------------------------------- cachefiles_lookup_cookie cachefiles_look_up_object lookup_one_positive_unlocked // get dentry cachefiles_cull inode->i_flags |= S_KERNEL_FILE; cachefiles_open_file cachefiles_mark_inode_in_use __cachefiles_mark_inode_in_use can_use = false if (!(inode->i_flags & S_KERNEL_FILE)) can_use = true return false return false // Returns an error but doesn't put dentry After that the following WARNING will be triggered when the backend folder is umounted: ================================================================== BUG: Dentry 000000008ad87947{i=7a,n=Dx_1_1.img} still in use (1) [unmount of ext4 sda] WARNING: CPU: 4 PID: 359261 at fs/dcache.c:1767 umount_check+0x5d/0x70 CPU: 4 PID: 359261 Comm: umount Not tainted 6.6.0-dirty #25 RIP: 0010:umount_check+0x5d/0x70 Call Trace: <TASK> d_walk+0xda/0x2b0 do_one_tree+0x20/0x40 shrink_dcache_for_umount+0x2c/0x90 generic_shutdown_super+0x20/0x160 kill_block_super+0x1a/0x40 ext4_kill_sb+0x22/0x40 deactivate_locked_super+0x35/0x80 cleanup_mnt+0x104/0x160 ================================================================== Whether cachefiles_open_file() returns true or false, the reference count obtained by lookup_positive_unlocked() in cachefiles_look_up_object() should be released. Therefore release that reference count in cachefiles_look_up_object() to fix the above issue and simplify the code. Added Reference kernel.org https://git.kernel.org/stable/c/d32ff64c872d7e08e893c32ba6a2374583444410 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/c7d10fa7d7691558ff967668494672415f5fa151 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/e4a28489b310339b2b8187bec0a437709be551c1 [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/7fa2382f97421978514a419c93054eca69f5247b [No types assigned] Added Reference kernel.org https://git.kernel.org/stable/c/da6ef2dffe6056aad3435e6cf7c6471c2a62187c [No types assigned]
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-49870 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-49870
weaknesses.