summaryrefslogtreecommitdiffstats
path: root/fs/fhandle.c
diff options
context:
space:
mode:
authorNikita Zhandarovich <n.zhandarovich@fintech.ru>2024-01-19 16:39:06 +0100
committerChristian Brauner <brauner@kernel.org>2024-01-22 15:33:38 +0100
commit3948abaa4e2be938ccdfc289385a27342fb13d43 (patch)
treee1b8d6b24add1bfb7891df80e0f803551a5a7f2e /fs/fhandle.c
parentwriteback: move wb_wakeup_delayed defination to fs-writeback.c (diff)
downloadlinux-3948abaa4e2be938ccdfc289385a27342fb13d43.tar.xz
linux-3948abaa4e2be938ccdfc289385a27342fb13d43.zip
do_sys_name_to_handle(): use kzalloc() to fix kernel-infoleak
syzbot identified a kernel information leak vulnerability in do_sys_name_to_handle() and issued the following report [1]. [1] "BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline] BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40 instrument_copy_to_user include/linux/instrumented.h:114 [inline] _copy_to_user+0xbc/0x100 lib/usercopy.c:40 copy_to_user include/linux/uaccess.h:191 [inline] do_sys_name_to_handle fs/fhandle.c:73 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Uninit was created at: slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768 slab_alloc_node mm/slub.c:3478 [inline] __kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0x121/0x3c0 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] do_sys_name_to_handle fs/fhandle.c:39 [inline] __do_sys_name_to_handle_at fs/fhandle.c:112 [inline] __se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94 __x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94 ... Bytes 18-19 of 20 are uninitialized Memory access of size 20 starts at ffff888128a46380 Data copied to user address 0000000020000240" Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to solve the problem. Fixes: 990d6c2d7aee ("vfs: Add name to file handle conversion support") Suggested-by: Chuck Lever III <chuck.lever@oracle.com> Reported-and-tested-by: <syzbot+09b349b3066c2e0b1e96@syzkaller.appspotmail.com> Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru> Link: https://lore.kernel.org/r/20240119153906.4367-1-n.zhandarovich@fintech.ru Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Christian Brauner <brauner@kernel.org>
Diffstat (limited to 'fs/fhandle.c')
-rw-r--r--fs/fhandle.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/fhandle.c b/fs/fhandle.c
index 18b3ba8dc8ea..57a12614addf 100644
--- a/fs/fhandle.c
+++ b/fs/fhandle.c
@@ -36,7 +36,7 @@ static long do_sys_name_to_handle(const struct path *path,
if (f_handle.handle_bytes > MAX_HANDLE_SZ)
return -EINVAL;
- handle = kmalloc(sizeof(struct file_handle) + f_handle.handle_bytes,
+ handle = kzalloc(sizeof(struct file_handle) + f_handle.handle_bytes,
GFP_KERNEL);
if (!handle)
return -ENOMEM;