I think I can fix this patch or the patchset of Heinrich Schuchardt could be applied
Mikhail Kshevetskiy On 25.06.2025 16:27, Michal Simek wrote: > [You don't often get email from mon...@monstr.eu. Learn why this is important > at https://aka.ms/LearnAboutSenderIdentification ] > > Hi Tom, > > út 24. 6. 2025 v 14:59 odesílatel Heinrich Schuchardt > <xypron.g...@gmx.de> napsal: >> On 10.06.25 11:56, Mikhail Kshevetskiy wrote: >>> The current code have two issues: >>> 1) ineffective NULL pointer check >>> >>> str = strchr(str, '\0') + 1 >>> if (!str || ... >>> >>> The str here will never be NULL (because we add 1 to result of strchr()) >>> >>> 2) strchr() may go out of the buffer for the special forms of name variable. >>> It's better use memchr() function here. >>> >>> According to the code the property is a sequence of C-string like >>> shown below: >>> >>> 'h', 'e', 'l', 'l', 'o', '\0', 'w', 'o', 'r', 'l', 'd', '\0', '!', >>> '\0' >>> >>> index is the string number we are interested, so >>> >>> index = 0 => "hello", >>> index = 1 => "world", >>> index = 2 => "!" >>> >>> The issue will arrise if last string for some reason have no terminating >>> '\0' character. This can happen for damaged or specially crafted dtb. >>> >>> Signed-off-by: Mikhail Kshevetskiy <mikhail.kshevets...@iopsys.eu> >>> Reviewed-by: Tom Rini <tr...@konsulko.com> >>> --- >>> common/spl/spl_fit.c | 5 +++-- >>> 1 file changed, 3 insertions(+), 2 deletions(-) >>> >>> diff --git a/common/spl/spl_fit.c b/common/spl/spl_fit.c >>> index 86506d6905c..ab277bb2baa 100644 >>> --- a/common/spl/spl_fit.c >>> +++ b/common/spl/spl_fit.c >>> @@ -86,11 +86,12 @@ static int spl_fit_get_image_name(const struct >>> spl_fit_info *ctx, >>> >>> str = name; >>> for (i = 0; i < index; i++) { >>> - str = strchr(str, '\0') + 1; >>> - if (!str || (str - name >= len)) { >>> + str = memchr(str, '\0', name + len - str); >>> + if (!str) { >>> found = false; >>> break; >>> } >>> + str++; >>> } >>> >>> if (!found && CONFIG_IS_ENABLED(SYSINFO) && !sysinfo_get(&sysinfo)) { >> Since this patch (commit 3704b888a4cabac8) on the Milk-V Mars board I >> see a message "cannot find image node ''" and on some builds I have seen >> boot failures. >> >> With your patch and some debug messages: >> >> U-Boot SPL 2025.07-rc4-00017-g3704b888a4ca-dirty (Jun 24 2025 - 14:45:11 >> +0200) >> DDR version: dc2e84f0. >> Trying to boot from MMC2 >> spl_fit_get_image_name(): index = 0, name = 'opensbi' len = 8 >> spl_fit_get_image_name(): outname = 'opensbi' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 0, name = 'fdt-2' len = 6 >> spl_fit_get_image_name(): outname = 'fdt-2' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 1, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = '' >> cannot find image node '': -1 >> >> >> Before that patch: >> >> U-Boot SPL 2025.07-rc4-00017-g3704b888a4ca-dirty (Jun 24 2025 - 14:34:50 >> +0200) >> DDR version: dc2e84f0. >> Trying to boot from MMC2 >> spl_fit_get_image_name(): index = 0, name = 'opensbi' len = 8 >> spl_fit_get_image_name(): outname = 'opensbi' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 0, name = 'fdt-2' len = 6 >> spl_fit_get_image_name(): outname = 'fdt-2' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 0, name = 'uboot' len = 6 >> spl_fit_get_image_name(): outname = 'uboot' >> spl_fit_get_image_name(): index = 1, name = 'uboot' len = 6 >> no string for index 1 >> >> >> With your patch spl_fit_get_image_name() does not detect that there is >> no property at index 1 and does not return -E2BIG. Instead it signals >> the property is an empty string and returns 0 which is not expected. >> > I also see random chars printed on the console on SOM with SPL flow. > This patch should be reverted. > > Thanks, > Michal > > -- > Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91 > w: http://www.monstr.eu/ p: +42-0-721842854 > Maintainer of Linux kernel - Xilinx Microblaze > Maintainer of Linux kernel - Xilinx Zynq ARM and ZynqMP ARM64 SoCs > U-Boot custodian - Xilinx Microblaze/Zynq/ZynqMP/Versal SoCs
