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DEBIAN-CVE-2025-21737
No affected components available
In the Linux kernel, the following vulnerability has been resolved: ceph: fix memory leak in ceph_mds_auth_match() We now free the temporary target path substring allocation on every possible branch, instead of omitting the default branch. In some cases, a memory leak occured, which could rapidly crash the system (depending on how many file accesses were attempted). This was detected in production because it caused a continuous memory growth, eventually triggering kernel OOM and completely hard-locking the kernel. Relevant kmemleak stacktrace: unreferenced object 0xffff888131e69900 (size 128): comm "git", pid 66104, jiffies 4295435999 hex dump (first 32 bytes): 76 6f 6c 75 6d 65 73 2f 63 6f 6e 74 61 69 6e 65 volumes/containe 72 73 2f 67 69 74 65 61 2f 67 69 74 65 61 2f 67 rs/gitea/gitea/g backtrace (crc 2f3bb450): [<ffffffffaa68fb49>] __kmalloc_noprof+0x359/0x510 [<ffffffffc32bf1df>] ceph_mds_check_access+0x5bf/0x14e0 [ceph] [<ffffffffc3235722>] ceph_open+0x312/0xd80 [ceph] [<ffffffffaa7dd786>] do_dentry_open+0x456/0x1120 [<ffffffffaa7e3729>] vfs_open+0x79/0x360 [<ffffffffaa832875>] path_openat+0x1de5/0x4390 [<ffffffffaa834fcc>] do_filp_open+0x19c/0x3c0 [<ffffffffaa7e44a1>] do_sys_openat2+0x141/0x180 [<ffffffffaa7e4945>] __x64_sys_open+0xe5/0x1a0 [<ffffffffac2cc2f7>] do_syscall_64+0xb7/0x210 [<ffffffffac400130>] entry_SYSCALL_64_after_hwframe+0x77/0x7f It can be triggered by mouting a subdirectory of a CephFS filesystem, and then trying to access files on this subdirectory with an auth token using a path-scoped capability: $ ceph auth get client.services [client.services] key = REDACTED caps mds = "allow rw fsname=cephfs path=/volumes/" caps mon = "allow r fsname=cephfs" caps osd = "allow rw tag cephfs data=cephfs" $ cat /proc/self/mounts services@[REDACTED].cephfs=/volumes/containers /ceph/containers ceph rw,noatime,name=services,secret=<hidden>,ms_mode=prefer-crc,mount_timeout=300,acl,mon_addr=[REDACTED]:3300,recover_session=clean 0 0 $ seq 1 1000000 | xargs -P32 --replace={} touch /ceph/containers/file-{} && \ seq 1 1000000 | xargs -P32 --replace={} cat /ceph/containers/file-{} [ idryomov: combine if statements, rename rc to path_matched and make it a bool, formatting ]
The vulnerability requires local access to the device to be exploited. It is easy for an attacker to exploit this vulnerability. An attacker needs basic access or low-level privileges. No user interaction is needed for the attacker to exploit this vulnerability. The impact is confined to the system where the vulnerability exists. There is a high impact on the availability of the system.
Exploitation attempts have been detected. Elevated vigilance and prompt remediation are advised.
Probability that this vulnerability will be exploited in the wild within the next 30 days.
We did not find any exploit available. Neither in GitHub repositories nor in the Exploit-Database.
- CVE-2025-21737Upstream
- EUVD-2025-5185Upstream
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