Alma Linux: CVE-2024-39501: Important: kernel security update (Multiple Advisories)
Description
In the Linux kernel, the following vulnerability has been resolved: drivers: core: synchronize really_probe() and dev_uevent() Synchronize the dev->driver usage in really_probe() and dev_uevent(). These can run in different threads, what can result in the following race condition for dev->driver uninitialization: Thread #1: ========== really_probe() { ... probe_failed: ... device_unbind_cleanup(dev) { ... dev->driver = NULL; // <= Failed probe sets dev->driver to NULL ... } ... } Thread #2: ========== dev_uevent() { ... if (dev->driver) // If dev->driver is NULLed from really_probe() from here on, // after above check, the system crashes add_uevent_var(env, "DRIVER=%s", dev->driver->name); ... } really_probe() holds the lock, already. So nothing needs to be done there. dev_uevent() is called with lock held, often, too. But not always. What implies that we can't add any locking in dev_uevent() itself. So fix this race by adding the lock to the non-protected path. This is the path where above race is observed: dev_uevent+0x235/0x380 uevent_show+0x10c/0x1f0 <= Add lock here dev_attr_show+0x3a/0xa0 sysfs_kf_seq_show+0x17c/0x250 kernfs_seq_show+0x7c/0x90 seq_read_iter+0x2d7/0x940 kernfs_fop_read_iter+0xc6/0x310 vfs_read+0x5bc/0x6b0 ksys_read+0xeb/0x1b0 __x64_sys_read+0x42/0x50 x64_sys_call+0x27ad/0x2d30 do_syscall_64+0xcd/0x1d0 entry_SYSCALL_64_after_hwframe+0x77/0x7f Similar cases are reported by syzkaller in https://syzkaller.appspot.com/bug?extid=ffa8143439596313a85a But these are regarding the *initialization* of dev->driver dev->driver = drv; As this switches dev->driver to non-NULL these reports can be considered to be false-positives (which should be "fixed" by this commit, as well, though). The same issue was reported and tried to be fixed back in 2015 in https://lore.kernel.org/lkml/1421259054-2574-1-git-send-email-a.sangwan@samsung.com/ already.
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
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