The strlcpy() reads the entire source buffer first, it is dangerous if the source buffer lenght is unbounded or possibility non NULL-terminated. It can lead to linear read overflows, crashes, etc...
As recommended in the deprecated interfaces [1], it should be replaced by strscpy. This commit replaces all calls to strlcpy that handle the return values by the corresponding strscpy calls with new handling of the return values (as it is quite different between the two functions). [1] https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy Signed-off-by: Romain Perier <romain.per...@gmail.com> --- kernel/trace/trace_uprobe.c | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 3cf7128e1ad3..f9583afdb735 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -154,12 +154,11 @@ fetch_store_string(unsigned long addr, void *dest, void *base) u8 *dst = get_loc_data(dest, base); void __user *src = (void __force __user *) addr; - if (unlikely(!maxlen)) - return -ENOMEM; - - if (addr == FETCH_TOKEN_COMM) - ret = strlcpy(dst, current->comm, maxlen); - else + if (addr == FETCH_TOKEN_COMM) { + ret = strscpy(dst, current->comm, maxlen); + if (ret == -E2BIG) + return -ENOMEM; + } else ret = strncpy_from_user(dst, src, maxlen); if (ret >= 0) { if (ret == maxlen)
