Alma Linux: CVE-2024-26935: Moderate: kernel security update (ALSA-2024-8617)
Description
In the Linux kernel, the following vulnerability has been resolved: scsi: core: Fix unremoved procfs host directory regression Commit fc663711b944 ("scsi: core: Remove the /proc/scsi/${proc_name} directory earlier") fixed a bug related to modules loading/unloading, by adding a call to scsi_proc_hostdir_rm() on scsi_remove_host(). But that led to a potential duplicate call to the hostdir_rm() routine, since it's also called from scsi_host_dev_release(). That triggered a regression report, which was then fixed by commit be03df3d4bfe ("scsi: core: Fix a procfs host directory removal regression"). The fix just dropped the hostdir_rm() call from dev_release(). But it happens that this proc directory is created on scsi_host_alloc(), and that function "pairs" with scsi_host_dev_release(), while scsi_remove_host() pairs with scsi_add_host(). In other words, it seems the reason for removing the proc directory on dev_release() was meant to cover cases in which a SCSI host structure was allocated, but the call to scsi_add_host() didn't happen. And that pattern happens to exist in some error paths, for example. Syzkaller causes that by using USB raw gadget device, error'ing on usb-storage driver, at usb_stor_probe2(). By checking that path, we can see that the BadDevice label leads to a scsi_host_put() after a SCSI host allocation, but there's no call to scsi_add_host() in such path. That leads to messages like this in dmesg (and a leak of the SCSI host proc structure): usb-storage 4-1:87.51: USB Mass Storage device detected proc_dir_entry 'scsi/usb-storage' already registered WARNING: CPU: 1 PID: 3519 at fs/proc/generic.c:377 proc_register+0x347/0x4e0 fs/proc/generic.c:376 The proper fix seems to still call scsi_proc_hostdir_rm() on dev_release(), but guard that with the state check for SHOST_CREATED; there is even a comment in scsi_host_dev_release() detailing that: such conditional is meant for cases where the SCSI host was allocated but there was no calls to {add,remove}_host(), like the usb-storage case. This is what we propose here and with that, the error path of usb-storage does not trigger the warning anymore.
Solution(s)
- alma-upgrade-bpftool
- alma-upgrade-kernel
- alma-upgrade-kernel-64k
- alma-upgrade-kernel-64k-core
- alma-upgrade-kernel-64k-debug
- alma-upgrade-kernel-64k-debug-core
- alma-upgrade-kernel-64k-debug-devel
- alma-upgrade-kernel-64k-debug-devel-matched
- alma-upgrade-kernel-64k-debug-modules
- alma-upgrade-kernel-64k-debug-modules-core
- alma-upgrade-kernel-64k-debug-modules-extra
- alma-upgrade-kernel-64k-devel
- alma-upgrade-kernel-64k-devel-matched
- alma-upgrade-kernel-64k-modules
- alma-upgrade-kernel-64k-modules-core
- alma-upgrade-kernel-64k-modules-extra
- 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-devel-matched
- alma-upgrade-kernel-debug-modules
- alma-upgrade-kernel-debug-modules-core
- alma-upgrade-kernel-debug-modules-extra
- alma-upgrade-kernel-debug-uki-virt
- alma-upgrade-kernel-devel
- alma-upgrade-kernel-devel-matched
- alma-upgrade-kernel-doc
- alma-upgrade-kernel-headers
- alma-upgrade-kernel-modules
- alma-upgrade-kernel-modules-core
- 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-modules
- alma-upgrade-kernel-rt-debug-modules-core
- alma-upgrade-kernel-rt-debug-modules-extra
- alma-upgrade-kernel-rt-devel
- alma-upgrade-kernel-rt-modules
- alma-upgrade-kernel-rt-modules-core
- alma-upgrade-kernel-rt-modules-extra
- alma-upgrade-kernel-tools
- alma-upgrade-kernel-tools-libs
- alma-upgrade-kernel-tools-libs-devel
- alma-upgrade-kernel-uki-virt
- alma-upgrade-kernel-zfcpdump
- alma-upgrade-kernel-zfcpdump-core
- alma-upgrade-kernel-zfcpdump-devel
- alma-upgrade-kernel-zfcpdump-devel-matched
- alma-upgrade-kernel-zfcpdump-modules
- alma-upgrade-kernel-zfcpdump-modules-core
- alma-upgrade-kernel-zfcpdump-modules-extra
- alma-upgrade-libperf
- alma-upgrade-perf
- alma-upgrade-python3-perf
- alma-upgrade-rtla
- alma-upgrade-rv
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