kernel/linux.git/fs/f2fs/sysfs.c, branch v6.6.131

f2fs: fix out-of-bounds access in sysfs attribute read/write

2026-02-19T15:28:27+00:00

commit 98ea0039dbfdd00e5cc1b9a8afa40434476c0955 upstream. Some f2fs sysfs attributes suffer from out-of-bounds memory access and incorrect handling of integer values whose size is not 4 bytes. For example: vm:~# echo 65537 > /sys/fs/f2fs/vde/carve_out vm:~# cat /sys/fs/f2fs/vde/carve_out 65537 vm:~# echo 4294967297 > /sys/fs/f2fs/vde/atgc_age_threshold vm:~# cat /sys/fs/f2fs/vde/atgc_age_threshold 1 carve_out maps to {struct f2fs_sb_info}->carve_out, which is a 8-bit integer. However, the sysfs interface allows setting it to a value larger than 255, resulting in an out-of-range update. atgc_age_threshold maps to {struct atgc_management}->age_threshold, which is a 64-bit integer, but its sysfs interface cannot correctly set values larger than UINT_MAX. The root causes are: 1. __sbi_store() treats all default values as unsigned int, which prevents updating integers larger than 4 bytes and causes out-of-bounds writes for integers smaller than 4 bytes. 2. f2fs_sbi_show() also assumes all default values are unsigned int, leading to out-of-bounds reads and incorrect access to integers larger than 4 bytes. This patch introduces {struct f2fs_attr}->size to record the actual size of the integer associated with each sysfs attribute. With this information, sysfs read and write operations can correctly access and update values according to their real data size, avoiding memory corruption and truncation. Fixes: b59d0bae6ca3 ("f2fs: add sysfs support for controlling the gc_thread") Cc: stable@kernel.org Signed-off-by: Jinbao Liu Signed-off-by: Yongpeng Yang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Greg Kroah-Hartman

f2fs: introduce f2fs_base_attr for global sysfs entries

2025-06-04T12:42:12+00:00

[ Upstream commit 21925ede449e038ed6f9efdfe0e79f15bddc34bc ] In /sys/fs/f2fs/features, there's no f2fs_sb_info, so let's avoid to get the pointer. Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: check validation of fault attrs in f2fs_build_fault_attr()

2024-07-11T10:49:09+00:00

[ Upstream commit 4ed886b187f47447ad559619c48c086f432d2b77 ] - It missed to check validation of fault attrs in parse_options(), let's fix to add check condition in f2fs_build_fault_attr(). - Use f2fs_build_fault_attr() in __sbi_store() to clean up code. Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim Signed-off-by: Sasha Levin

f2fs: use BLKS_PER_SEG, BLKS_PER_SEC, and SEGS_PER_SEC

2024-06-12T09:12:28+00:00

[ Upstream commit a60108f7dfb5867da1ad9c777d2fbbe47e4dbdd7 ] No functional change. Reviewed-by: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim Stable-dep-of: aa4074e8fec4 ("f2fs: fix block migration when section is not aligned to pow2") Signed-off-by: Sasha Levin

f2fs: fix to account cp stats correctly

2023-08-14T20:42:05+00:00

cp_foreground_calls sysfs entry shows total CP call count rather than foreground CP call count, fix it. Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to account gc stats correctly

2023-08-14T20:41:57+00:00

As reported, status debugfs entry shows inconsistent GC stats as below: GC calls: 6008 (BG: 6161) - data segments : 3053 (BG: 3053) - node segments : 2955 (BG: 2955) Total GC calls is larger than BGGC calls, the reason is: - f2fs_stat_info.call_count accounts total migrated section count by f2fs_gc() - f2fs_stat_info.bg_gc accounts total call times of f2fs_gc() from background gc_thread Another issue is gc_foreground_calls sysfs entry shows total GC call count rather than FGGC call count. This patch changes as below for fix: - account GC calls and migrated segment count separately - support to account migrated section count if it enables large section mode - fix to show correct value in gc_foreground_calls sysfs entry Fixes: fc7100ea2a52 ("f2fs: Add f2fs stats to sysfs") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: refactor struct f2fs_attr macro

2023-06-26T13:21:41+00:00

This patch provides a large number of variants of F2FS_RW_ATTR and F2FS_RO_ATTR macros, reducing the number of parameters required to initialize the f2fs_attr structure. Reported-by: kernel test robot Link: https://lore.kernel.org/oe-kbuild-all/202304152234.wjaY3IYm-lkp@intel.com/ Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: add sanity check for proc_mkdir

2023-05-08T18:18:04+00:00

Return -ENOMEM when proc_mkdir failed. Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: remove bulk remove_proc_entry() and unnecessary kobject_del()

2023-04-17T21:49:30+00:00

Convert to use remove_proc_subtree() and kill kobject_del() directly. kobject_put() actually covers kobject removal automatically, which is single stage removal. Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: convert to use sysfs_emit

2023-04-10T17:58:45+00:00

Let's use sysfs_emit. Signed-off-by: Yangtao Li Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim