I got a memleak report when doing some fuzz test: BUG: memory leak unreferenced object 0xffff888103f3da00 (size 64): comm "syz-executor.0", pid 2270, jiffies 4295404698 (age 46.593s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<000000004f2c0607>] kmalloc include/linux/slab.h:559 [inline] [<000000004f2c0607>] kzalloc include/linux/slab.h:666 [inline] [<000000004f2c0607>] proc_sys_call_handler+0x1d4/0x480 fs/proc/proc_sysctl.c:574 [<000000005ec6a16b>] call_write_iter include/linux/fs.h:1876 [inline] [<000000005ec6a16b>] new_sync_write+0x3c5/0x5b0 fs/read_write.c:515 [<00000000bbeebb83>] vfs_write+0x4e8/0x670 fs/read_write.c:595 [<000000009d967c93>] ksys_write+0x10c/0x220 fs/read_write.c:648 [<00000000139f6002>] do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46 [<00000000b7d61f44>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 Go to free buff when copy_from_iter_full() is failed. Fixes: 1dea05cbc0d7 ("sysctl: Convert to iter interfaces") Reported-by: Hulk Robot <hulkci@xxxxxxxxxx> Signed-off-by: Yang Yingliang <yangyingliang@xxxxxxxxxx> --- fs/proc/proc_sysctl.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index 9f6b9c3e3fda..a4a3122f8a58 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -578,7 +578,7 @@ static ssize_t proc_sys_call_handler(struct kiocb *iocb, struct iov_iter *iter, if (write) { error = -EFAULT; if (!copy_from_iter_full(kbuf, count, iter)) - goto out; + goto out_free_buf; kbuf[count] = '\0'; } -- 2.25.1