| Message ID | 20231130205607.work.463-kees@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 8a3750ecf8104de55c569ffbe844a85aa9d5deaa |
| Headers | show |
| Series | tracing/uprobe: Replace strlcpy() with strscpy() | expand |
On Thu, 30 Nov 2023 12:56:08 -0800 Kees Cook <keescook@chromium.org> wrote: > strlcpy() reads the entire source buffer first. This read may exceed > the destination size limit. This is both inefficient and can lead > to linear read overflows if a source string is not NUL-terminated[1]. > Additionally, it returns the size of the source string, not the > resulting size of the destination string. In an effort to remove strlcpy() > completely[2], replace strlcpy() here with strscpy(). > > The negative return value is already handled by this code so no new > handling is needed here. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1] > Link: https://github.com/KSPP/linux/issues/89 [2] > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: linux-trace-kernel@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Thanks for reporting! Let me pick this. Thanks! > --- > kernel/trace/trace_uprobe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 99c051de412a..a84b85d8aac1 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -151,7 +151,7 @@ fetch_store_string(unsigned long addr, void *dest, void *base) > return -ENOMEM; > > if (addr == FETCH_TOKEN_COMM) > - ret = strlcpy(dst, current->comm, maxlen); > + ret = strscpy(dst, current->comm, maxlen); > else > ret = strncpy_from_user(dst, src, maxlen); > if (ret >= 0) { > -- > 2.34.1 >
On Thu, 30 Nov 2023 12:56:08 -0800 Kees Cook <keescook@chromium.org> wrote: > strlcpy() reads the entire source buffer first. This read may exceed > the destination size limit. This is both inefficient and can lead > to linear read overflows if a source string is not NUL-terminated[1]. > Additionally, it returns the size of the source string, not the > resulting size of the destination string. In an effort to remove strlcpy() > completely[2], replace strlcpy() here with strscpy(). > > The negative return value is already handled by this code so no new > handling is needed here. > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1] > Link: https://github.com/KSPP/linux/issues/89 [2] > Cc: Steven Rostedt <rostedt@goodmis.org> > Cc: Masami Hiramatsu <mhiramat@kernel.org> > Cc: linux-trace-kernel@vger.kernel.org > Signed-off-by: Kees Cook <keescook@chromium.org> Hi Kees, As same as sample's change, should I ask you to pick this to your tree? Since it is a kind of a part of series patch. I'm OK for it since this does not change the code so much. In that case, please feel free to add my Ack. Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Thank you, > --- > kernel/trace/trace_uprobe.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c > index 99c051de412a..a84b85d8aac1 100644 > --- a/kernel/trace/trace_uprobe.c > +++ b/kernel/trace/trace_uprobe.c > @@ -151,7 +151,7 @@ fetch_store_string(unsigned long addr, void *dest, void *base) > return -ENOMEM; > > if (addr == FETCH_TOKEN_COMM) > - ret = strlcpy(dst, current->comm, maxlen); > + ret = strscpy(dst, current->comm, maxlen); > else > ret = strncpy_from_user(dst, src, maxlen); > if (ret >= 0) { > -- > 2.34.1 >
On Fri, Dec 01, 2023 at 03:27:26PM +0900, Masami Hiramatsu wrote: > On Thu, 30 Nov 2023 12:56:08 -0800 > Kees Cook <keescook@chromium.org> wrote: > > > strlcpy() reads the entire source buffer first. This read may exceed > > the destination size limit. This is both inefficient and can lead > > to linear read overflows if a source string is not NUL-terminated[1]. > > Additionally, it returns the size of the source string, not the > > resulting size of the destination string. In an effort to remove strlcpy() > > completely[2], replace strlcpy() here with strscpy(). > > > > The negative return value is already handled by this code so no new > > handling is needed here. > > > > Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1] > > Link: https://github.com/KSPP/linux/issues/89 [2] > > Cc: Steven Rostedt <rostedt@goodmis.org> > > Cc: Masami Hiramatsu <mhiramat@kernel.org> > > Cc: linux-trace-kernel@vger.kernel.org > > Signed-off-by: Kees Cook <keescook@chromium.org> > > Hi Kees, > > As same as sample's change, should I ask you to pick this to your tree? > Since it is a kind of a part of series patch. I'm OK for it since this > does not change the code so much. > > In that case, please feel free to add my Ack. > > Acked-by: Masami Hiramatsu (Google) <mhiramat@kernel.org> Either way is fine, but I can take it since I've got a few others already too. :) Thanks! -Kees
On Thu, 30 Nov 2023 12:56:08 -0800, Kees Cook wrote: > strlcpy() reads the entire source buffer first. This read may exceed > the destination size limit. This is both inefficient and can lead > to linear read overflows if a source string is not NUL-terminated[1]. > Additionally, it returns the size of the source string, not the > resulting size of the destination string. In an effort to remove strlcpy() > completely[2], replace strlcpy() here with strscpy(). > > [...] Applied to for-next/hardening, thanks! [1/1] tracing/uprobe: Replace strlcpy() with strscpy() https://git.kernel.org/kees/c/8a3750ecf810 Take care,
diff --git a/kernel/trace/trace_uprobe.c b/kernel/trace/trace_uprobe.c index 99c051de412a..a84b85d8aac1 100644 --- a/kernel/trace/trace_uprobe.c +++ b/kernel/trace/trace_uprobe.c @@ -151,7 +151,7 @@ fetch_store_string(unsigned long addr, void *dest, void *base) return -ENOMEM; if (addr == FETCH_TOKEN_COMM) - ret = strlcpy(dst, current->comm, maxlen); + ret = strscpy(dst, current->comm, maxlen); else ret = strncpy_from_user(dst, src, maxlen); if (ret >= 0) {
strlcpy() reads the entire source buffer first. This read may exceed the destination size limit. This is both inefficient and can lead to linear read overflows if a source string is not NUL-terminated[1]. Additionally, it returns the size of the source string, not the resulting size of the destination string. In an effort to remove strlcpy() completely[2], replace strlcpy() here with strscpy(). The negative return value is already handled by this code so no new handling is needed here. Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1] Link: https://github.com/KSPP/linux/issues/89 [2] Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: linux-trace-kernel@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org> --- kernel/trace/trace_uprobe.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)