Overview
About vulnerability
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to don’t dirty inode for readonly filesystem
syzbot reports f2fs bug as below:
kernel BUG at fs/f2fs/inode.c:933! RIP: 0010:f2fs_evict_inode+0x1576/0x1590 fs/f2fs/inode.c:933 Call Trace: evict+0x2a4/0x620 fs/inode.c:664 dispose_list fs/inode.c:697 [inline] evict_inodes+0x5f8/0x690 fs/inode.c:747 generic_shutdown_super+0x9d/0x2c0 fs/super.c:675 kill_block_super+0x44/0x90 fs/super.c:1667 kill_f2fs_super+0x303/0x3b0 fs/f2fs/super.c:4894 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 ptrace_notify+0x2cd/0x380 kernel/signal.c:2399 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:278 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x15c/0x280 kernel/entry/common.c:296 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x63/0x6b
The root cause is:
-
do_sys_open
-
f2fs_lookup
-
__f2fs_find_entry
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f2fs_i_depth_write
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f2fs_mark_inode_dirty_sync
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f2fs_dirty_inode
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set_inode_flag(inode, FI_DIRTY_INODE)
-
umount
-
kill_f2fs_super
-
kill_block_super
-
generic_shutdown_super
-
sync_filesystem : sb is readonly, skip sync_filesystem()
-
evict_inodes
-
iput
-
f2fs_evict_inode
-
f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE)) : trigger kernel panic
When we try to repair i_current_depth in readonly filesystem, let’s skip dirty inode to avoid panic in later f2fs_evict_inode().
Details
- Affected product:
- AlmaLinux 9.2 ESU , CentOS 6 ELS , CentOS 7 ELS , CentOS 8.4 ELS , CentOS 8.5 ELS , CentOS Stream 8 ELS , CloudLinux 6 ELS , CloudLinux 7 ELS , Oracle Linux 6 ELS , Oracle Linux 7 ELS , RHEL 7 ELS , Ubuntu 16.04 ELS , Ubuntu 18.04 ELS
- Affected packages:
- kernel @ 3.10.0 (+15 more)
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to don’t dirty inode for readonly filesystem
syzbot reports f2fs bug as below:
kernel BUG at fs/f2fs/inode.c:933! RIP: 0010:f2fs_evict_inode+0x1576/0x1590 fs/f2fs/inode.c:933 Call Trace: evict+0x2a4/0x620 fs/inode.c:664 dispose_list fs/inode.c:697 [inline] evict_inodes+0x5f8/0x690 fs/inode.c:747 generic_shutdown_super+0x9d/0x2c0 fs/super.c:675 kill_block_super+0x44/0x90 fs/super.c:1667 kill_f2fs_super+0x303/0x3b0 fs/f2fs/super.c:4894 deactivate_locked_super+0xc1/0x130 fs/super.c:484 cleanup_mnt+0x426/0x4c0 fs/namespace.c:1256 task_work_run+0x24a/0x300 kernel/task_work.c:180 ptrace_notify+0x2cd/0x380 kernel/signal.c:2399 ptrace_report_syscall include/linux/ptrace.h:411 [inline] ptrace_report_syscall_exit include/linux/ptrace.h:473 [inline] syscall_exit_work kernel/entry/common.c:251 [inline] syscall_exit_to_user_mode_prepare kernel/entry/common.c:278 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:283 [inline] syscall_exit_to_user_mode+0x15c/0x280 kernel/entry/common.c:296 do_syscall_64+0x50/0x110 arch/x86/entry/common.c:88 entry_SYSCALL_64_after_hwframe+0x63/0x6b
The root cause is:
-
do_sys_open
-
f2fs_lookup
-
__f2fs_find_entry
-
f2fs_i_depth_write
-
f2fs_mark_inode_dirty_sync
-
f2fs_dirty_inode
-
set_inode_flag(inode, FI_DIRTY_INODE)
-
umount
-
kill_f2fs_super
-
kill_block_super
-
generic_shutdown_super
-
sync_filesystem : sb is readonly, skip sync_filesystem()
-
evict_inodes
-
iput
-
f2fs_evict_inode
-
f2fs_bug_on(sbi, is_inode_flag_set(inode, FI_DIRTY_INODE)) : trigger kernel panic
When we try to repair i_current_depth in readonly filesystem, let’s skip dirty inode to avoid panic in later f2fs_evict_inode().