发布于3月6日3月6日 Members Alma Linux: CVE-2024-39276: Important: kernel security update (Multiple Advisories) Severity 4 CVSS (AV:L/AC:M/Au:N/C:P/I:P/A:P) Published 06/25/2024 Created 08/13/2024 Added 08/12/2024 Modified 09/20/2024 Description In the Linux kernel, the following vulnerability has been resolved: ext4: fix mb_cache_entry's e_refcnt leak in ext4_xattr_block_cache_find() Syzbot reports a warning as follows: ============================================ WARNING: CPU: 0 PID: 5075 at fs/mbcache.c:419 mb_cache_destroy+0x224/0x290 Modules linked in: CPU: 0 PID: 5075 Comm: syz-executor199 Not tainted 6.9.0-rc6-gb947cc5bf6d7 RIP: 0010:mb_cache_destroy+0x224/0x290 fs/mbcache.c:419 Call Trace: <TASK> ext4_put_super+0x6d4/0xcd0 fs/ext4/super.c:1375 generic_shutdown_super+0x136/0x2d0 fs/super.c:641 kill_block_super+0x44/0x90 fs/super.c:1675 ext4_kill_sb+0x68/0xa0 fs/ext4/super.c:7327 [...] ============================================ This is because when finding an entry in ext4_xattr_block_cache_find(), if ext4_sb_bread() returns -ENOMEM, the ce's e_refcnt, which has already grown in the __entry_find(), won't be put away, and eventually trigger the above issue in mb_cache_destroy() due to reference count leakage. So call mb_cache_entry_put() on the -ENOMEM error branch as a quick fix. Solution(s) alma-upgrade-bpftool alma-upgrade-kernel alma-upgrade-kernel-abi-stablelists alma-upgrade-kernel-core alma-upgrade-kernel-cross-headers alma-upgrade-kernel-debug alma-upgrade-kernel-debug-core alma-upgrade-kernel-debug-devel alma-upgrade-kernel-debug-modules alma-upgrade-kernel-debug-modules-extra alma-upgrade-kernel-devel alma-upgrade-kernel-doc alma-upgrade-kernel-headers alma-upgrade-kernel-modules alma-upgrade-kernel-modules-extra alma-upgrade-kernel-rt alma-upgrade-kernel-rt-core alma-upgrade-kernel-rt-debug alma-upgrade-kernel-rt-debug-core alma-upgrade-kernel-rt-debug-devel alma-upgrade-kernel-rt-debug-kvm alma-upgrade-kernel-rt-debug-modules alma-upgrade-kernel-rt-debug-modules-extra alma-upgrade-kernel-rt-devel alma-upgrade-kernel-rt-kvm alma-upgrade-kernel-rt-modules alma-upgrade-kernel-rt-modules-extra alma-upgrade-kernel-tools alma-upgrade-kernel-tools-libs alma-upgrade-kernel-tools-libs-devel alma-upgrade-kernel-zfcpdump alma-upgrade-kernel-zfcpdump-core alma-upgrade-kernel-zfcpdump-devel alma-upgrade-kernel-zfcpdump-modules alma-upgrade-kernel-zfcpdump-modules-extra alma-upgrade-perf alma-upgrade-python3-perf References https://attackerkb.com/topics/cve-2024-39276 CVE - 2024-39276 https://errata.almalinux.org/8/ALSA-2024-5101.html https://errata.almalinux.org/8/ALSA-2024-5102.html
