* Re: BUG: divide error in ubi_attach_mtd_dev [not found] <CA+UBctD_w=75wChmePZHp7KsBSNPWYGDBtzHPRPPtaFoqhGvXA@mail.gmail.com> @ 2023-04-18 5:16 ` Yu Hao 2023-04-18 6:30 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Yu Hao @ 2023-04-18 5:16 UTC (permalink / raw) To: richard, miquel.raynal, vigneshr, linux-mtd, linux-kernel Sorry that there is a mistake for the full report. It should be https://gist.github.com/ZHYfeng/ae66bf8167bc341d3753af00e9902b1a On Mon, Apr 17, 2023 at 10:10 PM Yu Hao <yhao016@ucr.edu> wrote: > > Hello, > > We found the following issue using syzkaller on Linux v6.2.0. > The full report: > https://gist.github.com/ZHYfeng/a3e3ff2bdfea5ed5de5475f0b54d55cb > > The brief report is below: > > ubi: mtd0 is already attached to ubi0 > ubi7: attaching mtd147 > divide error: 0000 [#1] PREEMPT SMP KASAN > CPU: 0 PID: 20023 Comm: syz-executor.0 Not tainted 6.2.0 #6 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > 1.13.0-1ubuntu1.1 04/01/2014 > RIP: 0010:mtd_div_by_eb include/linux/mtd/mtd.h:580 [inline] > RIP: 0010:io_init drivers/mtd/ubi/build.c:620 [inline] > RIP: 0010:ubi_attach_mtd_dev+0x77f/0x2fe0 drivers/mtd/ubi/build.c:955 > Code: fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 > d0 7c 08 84 d2 0f 85 1f 25 00 00 41 8b 4c 24 10 48 89 d8 31 d2 <48> f7 > f1 48 89 c3 e8 b6 f3 1b fc 48 8d 85 40 17 00 00 48 89 c2 48 > RSP: 0018:ffffc9000be0fd30 EFLAGS: 00010246 > RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > RDX: 0000000000000000 RSI: ffff888047a49d40 RDI: 0000000000000002 > RBP: ffff888024e1c000 R08: 0000000000000016 R09: fffff520017c1f47 > R10: ffffc9000be0fa37 R11: fffff520017c1f46 R12: ffff88806545a000 > R13: 0000000000000000 R14: ffff88806545a010 R15: 0000000000000007 > FS: 00007fd45e85c700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 00007f64aeef53a4 CR3: 000000004f39a000 CR4: 0000000000350ef0 > Call Trace: > <TASK> > ctrl_cdev_ioctl+0x303/0x3a0 drivers/mtd/ubi/cdev.c:1043 > vfs_ioctl fs/ioctl.c:51 [inline] > __do_sys_ioctl fs/ioctl.c:870 [inline] > __se_sys_ioctl fs/ioctl.c:856 [inline] > __x64_sys_ioctl+0x198/0x210 fs/ioctl.c:856 > do_syscall_x64 arch/x86/entry/common.c:50 [inline] > do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80 > entry_SYSCALL_64_after_hwframe+0x63/0xcd > RIP: 0033:0x7fd45d6902fd > Code: 02 b8 ff ff ff ff c3 66 0f 1f 44 00 00 f3 0f 1e fa 48 89 f8 48 > 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d > 01 f0 ff ff 73 01 c3 48 c7 c1 bc ff ff ff f7 d8 64 89 01 48 > RSP: 002b:00007fd45e85bc58 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 > RAX: ffffffffffffffda RBX: 00007fd45d7bbf60 RCX: 00007fd45d6902fd > RDX: 0000000020000000 RSI: 0000000040186f40 RDI: 0000000000000005 > RBP: 00007fd45d6fec89 R08: 0000000000000000 R09: 0000000000000000 > R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 > R13: 00007fff676814bf R14: 00007fff67681670 R15: 00007fd45e85bdc0 > </TASK> ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-18 5:16 ` BUG: divide error in ubi_attach_mtd_dev Yu Hao @ 2023-04-18 6:30 ` Richard Weinberger 2023-04-20 4:49 ` Zhihao Cheng 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-04-18 6:30 UTC (permalink / raw) To: Yu Hao; +Cc: Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel Yu Hao, ----- Ursprüngliche Mail ----- > Von: "Yu Hao" <yhao016@ucr.edu> >> ubi: mtd0 is already attached to ubi0 >> ubi7: attaching mtd147 >> divide error: 0000 [#1] PREEMPT SMP KASAN >> CPU: 0 PID: 20023 Comm: syz-executor.0 Not tainted 6.2.0 #6 >> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >> 1.13.0-1ubuntu1.1 04/01/2014 >> RIP: 0010:mtd_div_by_eb include/linux/mtd/mtd.h:580 [inline] >> RIP: 0010:io_init drivers/mtd/ubi/build.c:620 [inline] >> RIP: 0010:ubi_attach_mtd_dev+0x77f/0x2fe0 drivers/mtd/ubi/build.c:955 >> Code: fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 >> d0 7c 08 84 d2 0f 85 1f 25 00 00 41 8b 4c 24 10 48 89 d8 31 d2 <48> f7 >> f1 48 89 c3 e8 b6 f3 1b fc 48 8d 85 40 17 00 00 48 89 c2 48 >> RSP: 0018:ffffc9000be0fd30 EFLAGS: 00010246 >> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 >> RDX: 0000000000000000 RSI: ffff888047a49d40 RDI: 0000000000000002 >> RBP: ffff888024e1c000 R08: 0000000000000016 R09: fffff520017c1f47 >> R10: ffffc9000be0fa37 R11: fffff520017c1f46 R12: ffff88806545a000 >> R13: 0000000000000000 R14: ffff88806545a010 R15: 0000000000000007 >> FS: 00007fd45e85c700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000 >> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >> CR2: 00007f64aeef53a4 CR3: 000000004f39a000 CR4: 0000000000350ef0 >> Call Trace: >> <TASK> >> ctrl_cdev_ioctl+0x303/0x3a0 drivers/mtd/ubi/cdev.c:1043 What kind of MTD you attaching? Has it erasesize 0? Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-18 6:30 ` Richard Weinberger @ 2023-04-20 4:49 ` Zhihao Cheng 2023-04-20 17:27 ` Yu Hao 0 siblings, 1 reply; 15+ messages in thread From: Zhihao Cheng @ 2023-04-20 4:49 UTC (permalink / raw) To: Richard Weinberger, Yu Hao Cc: Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel Hi > Yu Hao, > > ----- Ursprüngliche Mail ----- >> Von: "Yu Hao" <yhao016@ucr.edu> >>> ubi: mtd0 is already attached to ubi0 >>> ubi7: attaching mtd147 >>> divide error: 0000 [#1] PREEMPT SMP KASAN >>> CPU: 0 PID: 20023 Comm: syz-executor.0 Not tainted 6.2.0 #6 >>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS >>> 1.13.0-1ubuntu1.1 04/01/2014 >>> RIP: 0010:mtd_div_by_eb include/linux/mtd/mtd.h:580 [inline] >>> RIP: 0010:io_init drivers/mtd/ubi/build.c:620 [inline] >>> RIP: 0010:ubi_attach_mtd_dev+0x77f/0x2fe0 drivers/mtd/ubi/build.c:955 >>> Code: fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 >>> d0 7c 08 84 d2 0f 85 1f 25 00 00 41 8b 4c 24 10 48 89 d8 31 d2 <48> f7 >>> f1 48 89 c3 e8 b6 f3 1b fc 48 8d 85 40 17 00 00 48 89 c2 48 >>> RSP: 0018:ffffc9000be0fd30 EFLAGS: 00010246 >>> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 >>> RDX: 0000000000000000 RSI: ffff888047a49d40 RDI: 0000000000000002 >>> RBP: ffff888024e1c000 R08: 0000000000000016 R09: fffff520017c1f47 >>> R10: ffffc9000be0fa37 R11: fffff520017c1f46 R12: ffff88806545a000 >>> R13: 0000000000000000 R14: ffff88806545a010 R15: 0000000000000007 >>> FS: 00007fd45e85c700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000 >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 >>> CR2: 00007f64aeef53a4 CR3: 000000004f39a000 CR4: 0000000000350ef0 >>> Call Trace: >>> <TASK> >>> ctrl_cdev_ioctl+0x303/0x3a0 drivers/mtd/ubi/cdev.c:1043 > > What kind of MTD you attaching? > Has it erasesize 0? > Yes, I agree with Richard's point, I guess UBI got an mtd device with zero erasesize. 568 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info *mtd) 569 { 570 if (mtd->erasesize_shift) // erasesize_shift is 0 571 return sz >> mtd->erasesize_shift; 572 do_div(sz, mtd->erasesize); // erasesize is 0 too 573 return sz; 574 } Yu Hao, how do you find the problem, by syzkaller? Can you provide the reproducing program or reproducing log? ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-20 4:49 ` Zhihao Cheng @ 2023-04-20 17:27 ` Yu Hao 2023-04-20 17:33 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Yu Hao @ 2023-04-20 17:27 UTC (permalink / raw) To: Zhihao Cheng Cc: Richard Weinberger, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel Hi, On Wed, Apr 19, 2023 at 9:49 PM Zhihao Cheng <chengzhihao1@huawei.com> wrote: > > Hi > > Yu Hao, > > > > ----- Ursprüngliche Mail ----- > >> Von: "Yu Hao" <yhao016@ucr.edu> > >>> ubi: mtd0 is already attached to ubi0 > >>> ubi7: attaching mtd147 > >>> divide error: 0000 [#1] PREEMPT SMP KASAN > >>> CPU: 0 PID: 20023 Comm: syz-executor.0 Not tainted 6.2.0 #6 > >>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS > >>> 1.13.0-1ubuntu1.1 04/01/2014 > >>> RIP: 0010:mtd_div_by_eb include/linux/mtd/mtd.h:580 [inline] > >>> RIP: 0010:io_init drivers/mtd/ubi/build.c:620 [inline] > >>> RIP: 0010:ubi_attach_mtd_dev+0x77f/0x2fe0 drivers/mtd/ubi/build.c:955 > >>> Code: fc ff df 48 c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 > >>> d0 7c 08 84 d2 0f 85 1f 25 00 00 41 8b 4c 24 10 48 89 d8 31 d2 <48> f7 > >>> f1 48 89 c3 e8 b6 f3 1b fc 48 8d 85 40 17 00 00 48 89 c2 48 > >>> RSP: 0018:ffffc9000be0fd30 EFLAGS: 00010246 > >>> RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000 > >>> RDX: 0000000000000000 RSI: ffff888047a49d40 RDI: 0000000000000002 > >>> RBP: ffff888024e1c000 R08: 0000000000000016 R09: fffff520017c1f47 > >>> R10: ffffc9000be0fa37 R11: fffff520017c1f46 R12: ffff88806545a000 > >>> R13: 0000000000000000 R14: ffff88806545a010 R15: 0000000000000007 > >>> FS: 00007fd45e85c700(0000) GS:ffff88802ca00000(0000) knlGS:0000000000000000 > >>> CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > >>> CR2: 00007f64aeef53a4 CR3: 000000004f39a000 CR4: 0000000000350ef0 > >>> Call Trace: > >>> <TASK> > >>> ctrl_cdev_ioctl+0x303/0x3a0 drivers/mtd/ubi/cdev.c:1043 > > > > What kind of MTD you attaching? > > Has it erasesize 0? > > > > Yes, I agree with Richard's point, I guess UBI got an mtd device with > zero erasesize. > The kernel is in qemu. We find that the `mtd` is from `mtd = get_mtd_device(NULL, req.mtd_num);` in function `ctrl_cdev_ioctl`. And we are still trying to figure out what MTD is. > > 568 static inline uint32_t mtd_div_by_eb(uint64_t sz, struct mtd_info > *mtd) > 569 { > 570 if (mtd->erasesize_shift) // erasesize_shift is 0 > 571 return sz >> mtd->erasesize_shift; > 572 do_div(sz, mtd->erasesize); // erasesize is 0 too > 573 return sz; > 574 } > > Yu Hao, how do you find the problem, by syzkaller? Can you provide the > reproducing program or reproducing log? We find this by syzkaller with customized syscall descriptions. There is not any reproducing program now. ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-20 17:27 ` Yu Hao @ 2023-04-20 17:33 ` Richard Weinberger 2023-04-20 18:14 ` Yu Hao 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-04-20 17:33 UTC (permalink / raw) To: Yu Hao Cc: chengzhihao1, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel ----- Ursprüngliche Mail ----- > The kernel is in qemu. We find that the `mtd` is from > `mtd = get_mtd_device(NULL, req.mtd_num);` in function `ctrl_cdev_ioctl`. > And we are still trying to figure out what MTD is. Can you please share the qemu command line? Within Linux you can query /proc/mtd or /sys/class/mtd/ to get infos about the MTD in question. Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-20 17:33 ` Richard Weinberger @ 2023-04-20 18:14 ` Yu Hao 2023-04-20 20:36 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Yu Hao @ 2023-04-20 18:14 UTC (permalink / raw) To: Richard Weinberger Cc: chengzhihao1, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel On Thu, Apr 20, 2023 at 10:33 AM Richard Weinberger <richard@nod.at> wrote: > > ----- Ursprüngliche Mail ----- > > The kernel is in qemu. We find that the `mtd` is from > > `mtd = get_mtd_device(NULL, req.mtd_num);` in function `ctrl_cdev_ioctl`. > > And we are still trying to figure out what MTD is. > > Can you please share the qemu command line? > qemu-system-x86_64 -m 2G -smp 2 -kernel /home/test/Workspace/SyzGen/linux-distro/linux-6.2-debug/arch/x86/boot/bzImage -append “console=ttyS0 root=/dev/sda net.ifnames=0” -hda /home/test/Workspace/SyzGen/linux-distro/image/stretch.img -chardev socket,id=SOCKSYZ,server=on,nowait,host=localhost,port=54640 -mon chardev=SOCKSYZ,mode=control -device virtio-rng-pci -device e1000,netdev=net0 -netdev user,id=net0,restrict=on,hostfwd=tcp:127.0.0.1:11760-:22 -display none -serial stdio -cpu host,migratable=off -no-reboot -name VM -snapshot -enable-kvm > Within Linux you can query /proc/mtd or /sys/class/mtd/ > to get infos about the MTD in question. > Thanks for the hints. We find that this is a “mtdram test device”. root@syzkaller:~# cat /proc/mtd dev: size erasesize name mtd0: 00020000 00001000 “mtdram test device” > Thanks, > //richard > ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-20 18:14 ` Yu Hao @ 2023-04-20 20:36 ` Richard Weinberger 2023-04-23 3:20 ` Zhihao Cheng 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-04-20 20:36 UTC (permalink / raw) To: Yu Hao Cc: chengzhihao1, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel ----- Ursprüngliche Mail ----- >> Can you please share the qemu command line? > qemu-system-x86_64 -m 2G -smp 2 -kernel > /home/test/Workspace/SyzGen/linux-distro/linux-6.2-debug/arch/x86/boot/bzImage > -append “console=ttyS0 root=/dev/sda net.ifnames=0” -hda > /home/test/Workspace/SyzGen/linux-distro/image/stretch.img -chardev > socket,id=SOCKSYZ,server=on,nowait,host=localhost,port=54640 -mon > chardev=SOCKSYZ,mode=control -device virtio-rng-pci -device > e1000,netdev=net0 -netdev > user,id=net0,restrict=on,hostfwd=tcp:127.0.0.1:11760-:22 -display none > -serial stdio -cpu host,migratable=off -no-reboot -name VM -snapshot > -enable-kvm > >> Within Linux you can query /proc/mtd or /sys/class/mtd/ >> to get infos about the MTD in question. >> > > Thanks for the hints. We find that this is a “mtdram test device”. > > root@syzkaller:~# cat /proc/mtd > dev: size erasesize name > mtd0: 00020000 00001000 “mtdram test device” Hmm, mtdram should be fine, erasesize is not zero. Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-20 20:36 ` Richard Weinberger @ 2023-04-23 3:20 ` Zhihao Cheng 2023-04-23 8:02 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Zhihao Cheng @ 2023-04-23 3:20 UTC (permalink / raw) To: Richard Weinberger, Yu Hao Cc: Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel 在 2023/4/21 4:36, Richard Weinberger 写道: > ----- Ursprüngliche Mail ----- >>> Can you please share the qemu command line? >> qemu-system-x86_64 -m 2G -smp 2 -kernel >> /home/test/Workspace/SyzGen/linux-distro/linux-6.2-debug/arch/x86/boot/bzImage >> -append “console=ttyS0 root=/dev/sda net.ifnames=0” -hda >> /home/test/Workspace/SyzGen/linux-distro/image/stretch.img -chardev >> socket,id=SOCKSYZ,server=on,nowait,host=localhost,port=54640 -mon >> chardev=SOCKSYZ,mode=control -device virtio-rng-pci -device >> e1000,netdev=net0 -netdev >> user,id=net0,restrict=on,hostfwd=tcp:127.0.0.1:11760-:22 -display none >> -serial stdio -cpu host,migratable=off -no-reboot -name VM -snapshot >> -enable-kvm >> >>> Within Linux you can query /proc/mtd or /sys/class/mtd/ >>> to get infos about the MTD in question. >>> >> >> Thanks for the hints. We find that this is a “mtdram test device”. >> >> root@syzkaller:~# cat /proc/mtd >> dev: size erasesize name >> mtd0: 00020000 00001000 “mtdram test device” > > Hmm, mtdram should be fine, erasesize is not zero. > I guess the zero-erasesize mtd device is dynamically generated in runtime, after looking through the code, I find erasesize is initiallized in specific flash driver and it won't be updated later(eg. ioctl\sysctl). And some mtd devices may have zero erasesize, eg. drivers/mtd/devices/mchp23k256.c[1]. Unfortunately, I don't know how to load/simulate this mtd, maybe it requires a real device? If we load this mtd device as ubi, it will trigger the problem? [1] https://cloud.tencent.com/developer/ask/sof/114616431 ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-23 3:20 ` Zhihao Cheng @ 2023-04-23 8:02 ` Richard Weinberger 2023-04-23 9:13 ` Zhihao Cheng 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-04-23 8:02 UTC (permalink / raw) To: chengzhihao1 Cc: Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel ----- Ursprüngliche Mail ----- > Von: "chengzhihao1" <chengzhihao1@huawei.com> >>> root@syzkaller:~# cat /proc/mtd >>> dev: size erasesize name >>> mtd0: 00020000 00001000 “mtdram test device” >> >> Hmm, mtdram should be fine, erasesize is not zero. >> > > I guess the zero-erasesize mtd device is dynamically generated in > runtime, after looking through the code, I find erasesize is > initiallized in specific flash driver and it won't be updated later(eg. > ioctl\sysctl). And some mtd devices may have zero erasesize, eg. > drivers/mtd/devices/mchp23k256.c[1]. Unfortunately, I don't know how to > load/simulate this mtd, maybe it requires a real device? If we load this > mtd device as ubi, it will trigger the problem? Indeed. I guess qemu can emulate such chips. So better fix UBI to reject attaching of mtd's with erasesize being 0. (Please note, we cannot test for MTD_NO_ERASE, this one means there is no erase method). Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-23 8:02 ` Richard Weinberger @ 2023-04-23 9:13 ` Zhihao Cheng 2023-10-02 10:11 ` Lee Jones 0 siblings, 1 reply; 15+ messages in thread From: Zhihao Cheng @ 2023-04-23 9:13 UTC (permalink / raw) To: Richard Weinberger Cc: Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel 在 2023/4/23 16:02, Richard Weinberger 写道: > ----- Ursprüngliche Mail ----- >> Von: "chengzhihao1" <chengzhihao1@huawei.com> >>>> root@syzkaller:~# cat /proc/mtd >>>> dev: size erasesize name >>>> mtd0: 00020000 00001000 “mtdram test device” >>> >>> Hmm, mtdram should be fine, erasesize is not zero. >>> >> >> I guess the zero-erasesize mtd device is dynamically generated in >> runtime, after looking through the code, I find erasesize is >> initiallized in specific flash driver and it won't be updated later(eg. >> ioctl\sysctl). And some mtd devices may have zero erasesize, eg. >> drivers/mtd/devices/mchp23k256.c[1]. Unfortunately, I don't know how to >> load/simulate this mtd, maybe it requires a real device? If we load this >> mtd device as ubi, it will trigger the problem? > > Indeed. I guess qemu can emulate such chips. > So better fix UBI to reject attaching of mtd's with erasesize being 0. > (Please note, we cannot test for MTD_NO_ERASE, this one means there is no > erase method). Phram is an exception, it has erase function but is set flag 'MTD_CAP_RAM'. May I interpret 'MTD_NO_ERASE' as erase function is not necessary? ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-04-23 9:13 ` Zhihao Cheng @ 2023-10-02 10:11 ` Lee Jones 2023-10-02 10:28 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Lee Jones @ 2023-10-02 10:11 UTC (permalink / raw) To: Zhihao Cheng Cc: Richard Weinberger, Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel On Sun, 23 Apr 2023, Zhihao Cheng wrote: > 在 2023/4/23 16:02, Richard Weinberger 写道: > > ----- Ursprüngliche Mail ----- > > > Von: "chengzhihao1" <chengzhihao1@huawei.com> > > > > > root@syzkaller:~# cat /proc/mtd > > > > > dev: size erasesize name > > > > > mtd0: 00020000 00001000 “mtdram test device” > > > > > > > > Hmm, mtdram should be fine, erasesize is not zero. > > > > > > > > > > I guess the zero-erasesize mtd device is dynamically generated in > > > runtime, after looking through the code, I find erasesize is > > > initiallized in specific flash driver and it won't be updated later(eg. > > > ioctl\sysctl). And some mtd devices may have zero erasesize, eg. > > > drivers/mtd/devices/mchp23k256.c[1]. Unfortunately, I don't know how to > > > load/simulate this mtd, maybe it requires a real device? If we load this > > > mtd device as ubi, it will trigger the problem? > > > > Indeed. I guess qemu can emulate such chips. > > So better fix UBI to reject attaching of mtd's with erasesize being 0. > > (Please note, we cannot test for MTD_NO_ERASE, this one means there is no > > erase method). > > Phram is an exception, it has erase function but is set flag 'MTD_CAP_RAM'. > May I interpret 'MTD_NO_ERASE' as erase function is not necessary? For better or worse, someone has applied to have this report associated with a CVE which means a bunch of companies and individuals are going to be tracking it. What is the current status please? Is this deemed to be a real issue? Did the report culminate in a posted patch? Any help would be gratefully received. -- Lee Jones [李琼斯] ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-10-02 10:11 ` Lee Jones @ 2023-10-02 10:28 ` Richard Weinberger 2023-10-02 14:04 ` Lee Jones 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-10-02 10:28 UTC (permalink / raw) To: Lee Jones Cc: chengzhihao1, Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel ----- Ursprüngliche Mail ----- > Von: "Lee Jones" <lee@kernel.org> > For better or worse, someone has applied to have this report associated > with a CVE which means a bunch of companies and individuals are going to > be tracking it. > > What is the current status please? I was about to answer that the patch is upstream, but it's only in linux-next. :-S After lunch I'll immediately send a PR. I messed up due to too much traveling the last months. > Is this deemed to be a real issue? I don't think so. Only the real root can install new MTD devices and run UBI attach. > Did the report culminate in a posted patch? Yes. As I said a patch is in next. Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-10-02 10:28 ` Richard Weinberger @ 2023-10-02 14:04 ` Lee Jones 2023-10-02 14:15 ` Richard Weinberger 0 siblings, 1 reply; 15+ messages in thread From: Lee Jones @ 2023-10-02 14:04 UTC (permalink / raw) To: Richard Weinberger Cc: chengzhihao1, Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel On Mon, 02 Oct 2023, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- > > Von: "Lee Jones" <lee@kernel.org> > > For better or worse, someone has applied to have this report associated > > with a CVE which means a bunch of companies and individuals are going to > > be tracking it. > > > > What is the current status please? > > I was about to answer that the patch is upstream, but it's only in linux-next. :-S > After lunch I'll immediately send a PR. I messed up due to too much traveling > the last months. > > > Is this deemed to be a real issue? > > I don't think so. Only the real root can install new MTD devices and run UBI attach. > > > Did the report culminate in a posted patch? > > Yes. As I said a patch is in next. Excellent, thanks. I'd like to track it. What's the subject please? -- Lee Jones [李琼斯] ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-10-02 14:04 ` Lee Jones @ 2023-10-02 14:15 ` Richard Weinberger 2023-10-02 14:36 ` Lee Jones 0 siblings, 1 reply; 15+ messages in thread From: Richard Weinberger @ 2023-10-02 14:15 UTC (permalink / raw) To: Lee Jones Cc: chengzhihao1, Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel ----- Ursprüngliche Mail ----- > Von: "Lee Jones" <lee@kernel.org> > Excellent, thanks. > > I'd like to track it. What's the subject please? "ubi: Refuse attaching if mtd's erasesize is 0" Thanks, //richard ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
* Re: BUG: divide error in ubi_attach_mtd_dev 2023-10-02 14:15 ` Richard Weinberger @ 2023-10-02 14:36 ` Lee Jones 0 siblings, 0 replies; 15+ messages in thread From: Lee Jones @ 2023-10-02 14:36 UTC (permalink / raw) To: Richard Weinberger Cc: chengzhihao1, Yu Hao, Miquel Raynal, Vignesh Raghavendra, linux-mtd, linux-kernel On Mon, 02 Oct 2023, Richard Weinberger wrote: > ----- Ursprüngliche Mail ----- > > Von: "Lee Jones" <lee@kernel.org> > > Excellent, thanks. > > > > I'd like to track it. What's the subject please? > > "ubi: Refuse attaching if mtd's erasesize is 0" That's great, thank you Richard. -- Lee Jones [李琼斯] ______________________________________________________ Linux MTD discussion mailing list http://lists.infradead.org/mailman/listinfo/linux-mtd/ ^ permalink raw reply [flat|nested] 15+ messages in thread
end of thread, other threads:[~2023-10-02 14:36 UTC | newest]
Thread overview: 15+ messages (download: mbox.gz follow: Atom feed
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2023-04-18 5:16 ` BUG: divide error in ubi_attach_mtd_dev Yu Hao
2023-04-18 6:30 ` Richard Weinberger
2023-04-20 4:49 ` Zhihao Cheng
2023-04-20 17:27 ` Yu Hao
2023-04-20 17:33 ` Richard Weinberger
2023-04-20 18:14 ` Yu Hao
2023-04-20 20:36 ` Richard Weinberger
2023-04-23 3:20 ` Zhihao Cheng
2023-04-23 8:02 ` Richard Weinberger
2023-04-23 9:13 ` Zhihao Cheng
2023-10-02 10:11 ` Lee Jones
2023-10-02 10:28 ` Richard Weinberger
2023-10-02 14:04 ` Lee Jones
2023-10-02 14:15 ` Richard Weinberger
2023-10-02 14:36 ` Lee Jones
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