# 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/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux-ld --version # < git log --format=%s --max-count=1 2e90ca68b0d2f5548804f22f0dd61145516171e3 # < make -s -j 80 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux- defconfig # < make -s -j 80 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux- help # make -s -j 80 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux- olddefconfig # make -s -j 80 ARCH=s390 O=/kisskb/build/linus_s390-defconfig_s390x CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/s390x-linux/bin/s390x-linux- /kisskb/src/kernel/printk/printk.c: In function 'devkmsg_sysctl_set_loglvl': /kisskb/src/kernel/printk/printk.c:204:16: warning: 'old' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/sched/core.c: In function 'try_to_wake_up': /kisskb/src/kernel/sched/core.c:2644:12: warning: 'cpu' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/fs/proc/inode.c:374:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/arch/s390/kernel/unwind_bc.c: In function '__unwind_start': /kisskb/src/arch/s390/kernel/unwind_bc.c:164:5: warning: 'ip' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/trace/trace_events.c: In function 'event_create_dir': /kisskb/src/kernel/trace/trace_events.c:2040:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec': /kisskb/src/fs/ext4/extents.c:5009:23: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/gfs2/lops.c: In function 'gfs2_find_jhead': /kisskb/src/fs/gfs2/lops.c:564:8: warning: 'off' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/ocfs2/alloc.c: In function 'ocfs2_trim_mainbm': /kisskb/src/fs/ocfs2/alloc.c:7608:17: warning: 'first_bit' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c: In function 'tun_get_user': /kisskb/src/drivers/net/tun.c:1836:30: warning: 'copylen' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/net/tun.c:1749:46: warning: 'linear' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2151:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/nfsd/nfs4xdr.c:2156:42: warning: 'end' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/core/devlink.c: In function 'devlink_fmsg_prepare_skb': /kisskb/src/net/core/devlink.c:4619:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/mm/hugetlb.c: In function 'alloc_pool_huge_page': /kisskb/src/mm/hugetlb.c:1426:5: warning: 'page' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/bridge/br_netlink.c: In function 'br_process_vlan_info': /kisskb/src/net/bridge/br_netlink.c:571:6: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/kernel/padata.c: In function 'padata_replace': /kisskb/src/kernel/padata.c:539:2: warning: 'err' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/io_uring.c: In function '__io_sqe_files_update': /kisskb/src/fs/io_uring.c:5819:13: warning: 'err' may be used uninitialized in this function [-Wuninitialized] Completed OK # rm -rf /kisskb/build/linus_s390-defconfig_s390x # Build took: 0:05:15.896512