CVE-2024-35849

En el kernel de Linux, se resolvió la siguiente vulnerabilidad: btrfs: corrige la fuga de información en btrfs_ioctl_logic_to_ino() Syzbot informó la siguiente fuga de información en btrfs_ioctl_logic_to_ino(): ERROR: KMSAN: kernel-infoleak en instrument_copy_to_user include/linux/instrumented.h: 114 [en línea] ERROR: KMSAN: kernel-infoleak en _copy_to_user+0xbc/0x110 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [en línea] _copy_to_user+0xbc/0x110 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [en línea] btrfs_ioctl_logic_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [en línea] __do_sys_ioctl fs/ioctl.c :904 [en línea] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h: 17 do_syscall_x64 arco/ x86/entry/common.c:52 [en línea] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit se creó en: __kmalloc_large_node+0x231/0x370 mm/slub.c:3921 __do_kmalloc_node mm/slub.c:3954 [en línea] __kmalloc_node+0xb07/0x1060 mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [en línea] kvmalloc_node+0xc0/0x2d0 mm/util.c:634 kvmalloc incluye /linux/slab.h:766 [en línea] init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779 btrfs_ioctl_logic_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480 btrfs_ioctl+0x714/0x1260 ctl fs/ioctl.c :51 [en línea] __do_sys_ioctl fs/ioctl.c:904 [en línea] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x Arco 3b50/x86/incluye /generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [en línea] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 Entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 40-65535 de 65536 no están inicializados El acceso a la memoria de tamaño 65536 comienza en ffff888045a40000. Esto sucede porque estamos copiando una 'estructura btrfs_data_container' nuevamente al espacio de usuario. Este btrfs_data_container se asigna en 'init_data_container()' a través de kvmalloc(), que no llena la memoria con ceros. Solucione este problema usando kvzalloc() que pone a cero la memoria al asignarla.

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix information leak in btrfs_ioctl_logical_to_ino() Syzbot reported the following information leak for in btrfs_ioctl_logical_to_ino(): BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x110 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x110 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] btrfs_ioctl_logical_to_ino+0x440/0x750 fs/btrfs/ioctl.c:3499 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Uninit was created at: __kmalloc_large_node+0x231/0x370 mm/slub.c:3921 __do_kmalloc_node mm/slub.c:3954 [inline] __kmalloc_node+0xb07/0x1060 mm/slub.c:3973 kmalloc_node include/linux/slab.h:648 [inline] kvmalloc_node+0xc0/0x2d0 mm/util.c:634 kvmalloc include/linux/slab.h:766 [inline] init_data_container+0x49/0x1e0 fs/btrfs/backref.c:2779 btrfs_ioctl_logical_to_ino+0x17c/0x750 fs/btrfs/ioctl.c:3480 btrfs_ioctl+0x714/0x1260 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:904 [inline] __se_sys_ioctl+0x261/0x450 fs/ioctl.c:890 __x64_sys_ioctl+0x96/0xe0 fs/ioctl.c:890 x64_sys_call+0x1883/0x3b50 arch/x86/include/generated/asm/syscalls_64.h:17 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x1e0 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Bytes 40-65535 of 65536 are uninitialized Memory access of size 65536 starts at ffff888045a40000 This happens, because we're copying a 'struct btrfs_data_container' back to user-space. This btrfs_data_container is allocated in 'init_data_container()' via kvmalloc(), which does not zero-fill the memory. Fix this by using kvzalloc() which zeroes out the memory on allocation.

Benedict Schlüter, Supraja Sridhara, Andrin Bertschi, and Shweta Shinde discovered that an untrusted hypervisor could inject malicious #VC interrupts and compromise the security guarantees of AMD SEV-SNP. This flaw is known as WeSee. A local attacker in control of the hypervisor could use this to expose sensitive information or possibly execute arbitrary code in the trusted execution environment. Several security issues were discovered in the Linux kernel. An attacker could possibly use these to compromise the system.