# git rev-parse -q --verify a5b9b743fdb653c37d347b303fb60dff0c743f7e^{commit} a5b9b743fdb653c37d347b303fb60dff0c743f7e already have revision, skipping fetch # git checkout -q -f -B kisskb a5b9b743fdb653c37d347b303fb60dff0c743f7e # git clean -qxdf # < git log -1 # commit a5b9b743fdb653c37d347b303fb60dff0c743f7e # Author: Frederic Barrat # Date: Mon Jun 24 16:41:48 2019 +0200 # # ocxl: Fix concurrent AFU open and device removal # # If an ocxl device is unbound through sysfs at the same time its AFU is # being opened by a user process, the open code may dereference freed # stuctures, which can lead to kernel oops messages. You'd have to hit a # tiny time window, but it's possible. It's fairly easy to test by # making the time window bigger artificially. # # Fix it with a combination of 2 changes: # - when an AFU device is found in the IDR by looking for the device # minor number, we should hold a reference on the device until after # the context is allocated. A reference on the AFU structure is kept # when the context is allocated, so we can release the reference on # the device after the context allocation. # - with the fix above, there's still another even tinier window, # between the time the AFU device is found in the IDR and the # reference on the device is taken. We can fix this one by removing # the IDR entry earlier, when the device setup is removed, instead # of waiting for the 'release' device callback. With proper locking # around the IDR. # # Fixes: 75ca758adbaf ("ocxl: Create a clear delineation between ocxl backend & frontend") # Cc: stable@vger.kernel.org # v5.2+ # Signed-off-by: Frederic Barrat # Reviewed-by: Greg Kurz # Signed-off-by: Michael Ellerman # Link: https://lore.kernel.org/r/20190624144148.32022-1-fbarrat@linux.ibm.com # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-gcc --version # < /opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux-ld --version # < git log --format=%s --max-count=1 a5b9b743fdb653c37d347b303fb60dff0c743f7e # < make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- pmac32_defconfig # Added to kconfig configs/2006/11/29/pmac32_defconfigkexec # yes \n | make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-linux- oldconfig yes: standard output: Broken pipe # make -s -j 32 ARCH=powerpc O=/kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc4.6 CROSS_COMPILE=/opt/cross/kisskb/gcc-4.6.3-nolibc/powerpc-linux/bin/powerpc-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/fs/ext4/extents.c: In function 'ext4_convert_unwritten_io_end_vec': /kisskb/src/fs/ext4/extents.c:5054:23: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/ppc/awacs.c: In function 'snd_pmac_awacs_init': /kisskb/src/include/sound/control.h:208:2: warning: 'speaker_vol' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/sound/ppc/awacs.c:873:36: note: 'speaker_vol' was declared here /kisskb/src/drivers/base/regmap/regmap.c: In function 'regmap_raw_read': /kisskb/src/drivers/base/regmap/regmap.c:2591:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/base/regmap/regmap.c: In function '_regmap_raw_write': /kisskb/src/drivers/base/regmap/regmap.c:1852:6: warning: 'ret' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c: In function 'proc_reg_open': /kisskb/src/include/linux/list.h:65:12: warning: 'pdeo' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/proc/inode.c:338:21: note: 'pdeo' was declared here /kisskb/src/fs/nfsd/nfs4xdr.c: In function 'nfsd4_encode_components_esc': /kisskb/src/fs/nfsd/nfs4xdr.c:2076:9: warning: 'str' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/fs/udf/unicode.c: In function 'udf_name_conv_char': /kisskb/src/fs/udf/unicode.c:132:8: warning: 'c' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c: In function 'univ8250_release_irq': /kisskb/src/drivers/tty/serial/8250/8250_core.c:248:18: warning: 'i' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/drivers/tty/serial/8250/8250_core.c:228:19: note: 'i' was declared here /kisskb/src/net/mac80211/mlme.c: In function 'ieee80211_rx_mgmt_beacon': /kisskb/src/net/mac80211/mlme.c:1576:3: warning: 'pwr_level_cisco' may be used uninitialized in this function [-Wuninitialized] /kisskb/src/net/mac80211/mlme.c:1533:6: note: 'pwr_level_cisco' was declared here /kisskb/src/drivers/usb/core/devio.c: In function 'async_completed': /kisskb/src/drivers/usb/core/devio.c:625:23: warning: 'errno' 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/drivers/net/wireless/broadcom/b43/phy_n.c: In function 'b43_nphy_rf_ctl_override_rev7': /kisskb/src/drivers/net/wireless/broadcom/b43/phy_n.c:190:21: warning: 'val_addr' may be used uninitialized in this function [-Wuninitialized] INFO: Uncompressed kernel (size 0x8630e0) overlaps the address of the wrapper(0x400000) INFO: Fixing the link_address of wrapper to (0x900000) Completed OK # rm -rf /kisskb/build/powerpc-fixes_pmac32_defconfig+kexec_powerpc-gcc4.6 # Build took: 0:01:33.504959