From 1bd1d033377796418008e9a2351f18dbdf88940c Mon Sep 17 00:00:00 2001 From: Francois Berder Date: Sun, 24 May 2026 21:25:47 +0200 Subject: [PATCH] fastboot: Fix blk_dwrite error checking blk_dwrite() returns the number of blocks written. The code was only checking if the return value was different than 0. Hence, partial writes were considered successful. Fix blk_dwrite error handling by checking that all blocks are written. Signed-off-by: Francois Berder Reviewed-by: Mattijs Korpershoek Link: https://patch.msgid.link/BESP194MB2805BBD03E7C92727F116585DA0D2@BESP194MB2805.EURP194.PROD.OUTLOOK.COM Signed-off-by: Mattijs Korpershoek --- drivers/fastboot/fb_mmc.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/drivers/fastboot/fb_mmc.c b/drivers/fastboot/fb_mmc.c index 11d9c8e8460..9bc782ccd02 100644 --- a/drivers/fastboot/fb_mmc.c +++ b/drivers/fastboot/fb_mmc.c @@ -263,7 +263,7 @@ static int fb_mmc_update_zimage(struct blk_desc *dev_desc, /* Write new kernel size to boot image header */ hdr->kernel_size = download_bytes; res = blk_dwrite(dev_desc, info.start, hdr_sectors, (void *)hdr); - if (res == 0) { + if (res != hdr_sectors) { pr_err("cannot writeback boot image header\n"); fastboot_fail("cannot write back boot image header", response); return -1; @@ -275,7 +275,7 @@ static int fb_mmc_update_zimage(struct blk_desc *dev_desc, sectors_per_page; res = blk_dwrite(dev_desc, kernel_sector_start, kernel_sectors, download_buffer); - if (res == 0) { + if (res != kernel_sectors) { pr_err("cannot write new kernel\n"); fastboot_fail("cannot write new kernel", response); return -1; @@ -287,7 +287,7 @@ static int fb_mmc_update_zimage(struct blk_desc *dev_desc, sectors_per_page; res = blk_dwrite(dev_desc, ramdisk_sector_start, ramdisk_sectors, ramdisk_buffer); - if (res == 0) { + if (res != ramdisk_sectors) { pr_err("cannot write back original ramdisk\n"); fastboot_fail("cannot write back original ramdisk", response); return -1;