CVE-2023-53344
Vulnérabilité moyenne dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: can: bcm: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write Syzkaller reported the following issue: ===================================================== BUG: KMSAN: uninit-value in aio_rw_done fs/aio.c:1520 [inline] BUG: KMSAN: uninit-value in aio_write+0x899/0x950 fs/aio.c:1600 aio_rw_done fs/aio.c:1520 [inline] aio_write+0x899/0x950 fs/aio.c:1600 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019 __do_sys_io_submit fs/aio.c:2078 [inline] __se_sys_io_submit+0x293/0x770 fs/aio.c:2048 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd Uninit was created at: slab_post_alloc_hook mm/slab.h:766 [inline] slab_alloc_node mm/slub.c:3452 [inline] __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491 __do_kmalloc_node mm/slab_common.c:967 [inline] __kmalloc+0x11d/0x3b0 mm/slab_common.c:981 kmalloc_array include/linux/slab.h:636 [inline] bcm_tx_setup+0x80e/0x29d0 net/can/bcm.c:930 bcm_sendmsg+0x3a2/0xce0 net/can/bcm.c:1351 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] sock_write_iter+0x495/0x5e0 net/socket.c:1108 call_write_iter include/linux/fs.h:2189 [inline] aio_write+0x63a/0x950 fs/aio.c:1600 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019 __do_sys_io_submit fs/aio.c:2078 [inline] __se_sys_io_submit+0x293/0x770 fs/aio.c:2048 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x63/0xcd CPU: 1 PID: 5034 Comm: syz-executor350 Not tainted 6.2.0-rc6-syzkaller-80422-geda666ff2276 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023 ===================================================== We can follow the call chain and find that 'bcm_tx_setup' function calls 'memcpy_from_msg' to copy some content to the newly allocated frame of 'op->frames'. After that the 'len' field of copied structure being compared with some constant value (64 or 8). However, if 'memcpy_from_msg' returns an error, we will compare some uninitialized memory. This triggers 'uninit-value' issue. This patch will add 'memcpy_from_msg' possible errors processing to avoid uninit-value issue. Tested via syzkaller
Gravité et risque d'exploitation
CVE-2023-53344 obtient un score CVSS de 5.5/10, soit une gravité moyenne. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.20 %, ce qui la place devant 9.7 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6f3b911d5f29b98752e5da86a295210c0c4f4e14, <=6.1.*, 4.19.280, <618b15d09fed6126356101543451d49860db4388, <3fa0f1e0e31b1b73cdf59d4c36c7242e6ef821be, <bf70e0eab64c625da84d9fdf4e84466b79418920, 0, <c11dbc7705b3739974ac31a13f4ab81e61a5fb07, 5.10.177, <78bc7f0ab99458221224d3ab97199c0f8e6861f1, <=5.10.*, <=4.14.*, 5.15.106, 6.3, <ab2a55907823f0bca56b6d03ea05e4071ba8535f, <=5.4.*, 6.1.23, <=4.19.*, 4.14.312, <=6.2.*, <2e6ad51c709fa794e0ce26003c9c9cd944e3383a, 4.8, 5.4.240, <=*, <=5.15.*, <4.8, <2b4c99f7d9a57ecd644eda9b1fb0a1072414959f, 6.2.10) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.
Références
- https://git.kernel.org/stable/c/3fa0f1e0e31b1b73cdf59d4c36c7242e6ef821be
- https://git.kernel.org/stable/c/618b15d09fed6126356101543451d49860db4388
- https://git.kernel.org/stable/c/78bc7f0ab99458221224d3ab97199c0f8e6861f1
- https://git.kernel.org/stable/c/ab2a55907823f0bca56b6d03ea05e4071ba8535f
- https://git.kernel.org/stable/c/bf70e0eab64c625da84d9fdf4e84466b79418920
- https://git.kernel.org/stable/c/c11dbc7705b3739974ac31a13f4ab81e61a5fb07
- https://git.kernel.org/stable/c/2e6ad51c709fa794e0ce26003c9c9cd944e3383a
- https://git.kernel.org/stable/c/2b4c99f7d9a57ecd644eda9b1fb0a1072414959f
