# git rev-parse -q --verify 2e90ca68b0d2f5548804f22f0dd61145516171e3^{commit} 2e90ca68b0d2f5548804f22f0dd61145516171e3 already have revision, skipping fetch # git checkout -q -f -B kisskb 2e90ca68b0d2f5548804f22f0dd61145516171e3 # git clean -qxdf # < git log -1 # commit 2e90ca68b0d2f5548804f22f0dd61145516171e3 # Author: Linus Torvalds # Date: Fri Feb 21 12:43:35 2020 -0800 # # floppy: check FDC index for errors before assigning it # # Jordy Zomer reported a KASAN out-of-bounds read in the floppy driver in # wait_til_ready(). # # Which on the face of it can't happen, since as Willy Tarreau points out, # the function does no particular memory access. Except through the FDCS # macro, which just indexes a static allocation through teh current fdc, # which is always checked against N_FDC. # # Except the checking happens after we've already assigned the value. # # The floppy driver is a disgrace (a lot of it going back to my original # horrd "design"), and has no real maintainer. Nobody has the hardware, # and nobody really cares. But it still gets used in virtual environment # because it's one of those things that everybody supports. # # The whole thing should be re-written, or at least parts of it should be # seriously cleaned up. The 'current fdc' index, which is used by the # FDCS macro, and which is often shadowed by a local 'fdc' variable, is a # prime example of how not to write code. # # But because nobody has the hardware or the motivation, let's just fix up # the immediate problem with a nasty band-aid: test the fdc index before # actually assigning it to the static 'fdc' variable. # # Reported-by: Jordy Zomer # Cc: Willy Tarreau # Cc: Dan Carpenter # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 2e90ca68b0d2f5548804f22f0dd61145516171e3 # < make -s -j 160 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- 44x/fsp2_defconfig # < make -s -j 160 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 160 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 160 ARCH=powerpc O=/kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- INFO: Uncompressed kernel (size 0x95748c) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0xa00000) Image Name: Linux-5.6.0-rc3-g2e90ca68b0d2 Created: Wed Feb 26 02:02:53 2020 Image Type: PowerPC Linux Kernel Image (gzip compressed) Data Size: 4206497 Bytes = 4107.91 KiB = 4.01 MiB Load Address: 00000000 Entry Point: 00000000 Completed OK # rm -rf /kisskb/build/linus_44x_fsp2_defconfig_powerpc-gcc5 # Build took: 0:00:38.121435