From: Greg Kroah-Hartman Date: Sun, 23 Jan 2022 16:15:58 +0000 (+0100) Subject: 4.4-stable patches X-Git-Tag: v4.4.300~127 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=977e4cf44bb4e42ae04641606c6fcc41fc5635fc;p=thirdparty%2Fkernel%2Fstable-queue.git 4.4-stable patches added patches: ubifs-error-path-in-ubifs_remount_rw-seems-to-wrongly-free-write-buffers.patch --- diff --git a/queue-4.4/series b/queue-4.4/series index 1b422b3b63f..c368611c630 100644 --- a/queue-4.4/series +++ b/queue-4.4/series @@ -94,3 +94,4 @@ i2c-designware-pci-fix-to-change-data-types-of-hcnt-.patch mips-octeon-fix-build-errors-using-clang.patch scsi-sr-don-t-use-gfp_dma.patch power-bq25890-enable-continuous-conversion-for-adc-a.patch +ubifs-error-path-in-ubifs_remount_rw-seems-to-wrongly-free-write-buffers.patch diff --git a/queue-4.4/ubifs-error-path-in-ubifs_remount_rw-seems-to-wrongly-free-write-buffers.patch b/queue-4.4/ubifs-error-path-in-ubifs_remount_rw-seems-to-wrongly-free-write-buffers.patch new file mode 100644 index 00000000000..a6e5bd7ab25 --- /dev/null +++ b/queue-4.4/ubifs-error-path-in-ubifs_remount_rw-seems-to-wrongly-free-write-buffers.patch @@ -0,0 +1,105 @@ +From 3fea4d9d160186617ff40490ae01f4f4f36b28ff Mon Sep 17 00:00:00 2001 +From: Petr Cvachoucek +Date: Mon, 30 Aug 2021 21:20:37 +0200 +Subject: ubifs: Error path in ubifs_remount_rw() seems to wrongly free write buffers + +From: Petr Cvachoucek + +commit 3fea4d9d160186617ff40490ae01f4f4f36b28ff upstream. + +it seems freeing the write buffers in the error path of the +ubifs_remount_rw() is wrong. It leads later to a kernel oops like this: + +[10016.431274] UBIFS (ubi0:0): start fixing up free space +[10090.810042] UBIFS (ubi0:0): free space fixup complete +[10090.814623] UBIFS error (ubi0:0 pid 512): ubifs_remount_fs: cannot +spawn "ubifs_bgt0_0", error -4 +[10101.915108] UBIFS (ubi0:0): background thread "ubifs_bgt0_0" started, +PID 517 +[10105.275498] Unable to handle kernel NULL pointer dereference at +virtual address 0000000000000030 +[10105.284352] Mem abort info: +[10105.287160] ESR = 0x96000006 +[10105.290252] EC = 0x25: DABT (current EL), IL = 32 bits +[10105.295592] SET = 0, FnV = 0 +[10105.298652] EA = 0, S1PTW = 0 +[10105.301848] Data abort info: +[10105.304723] ISV = 0, ISS = 0x00000006 +[10105.308573] CM = 0, WnR = 0 +[10105.311564] user pgtable: 4k pages, 48-bit VAs, pgdp=00000000f03d1000 +[10105.318034] [0000000000000030] pgd=00000000f6cee003, +pud=00000000f4884003, pmd=0000000000000000 +[10105.326783] Internal error: Oops: 96000006 [#1] PREEMPT SMP +[10105.332355] Modules linked in: ath10k_pci ath10k_core ath mac80211 +libarc4 cfg80211 nvme nvme_core cryptodev(O) +[10105.342468] CPU: 3 PID: 518 Comm: touch Tainted: G O +5.4.3 #1 +[10105.349517] Hardware name: HYPEX CPU (DT) +[10105.353525] pstate: 40000005 (nZcv daif -PAN -UAO) +[10105.358324] pc : atomic64_try_cmpxchg_acquire.constprop.22+0x8/0x34 +[10105.364596] lr : mutex_lock+0x1c/0x34 +[10105.368253] sp : ffff000075633aa0 +[10105.371563] x29: ffff000075633aa0 x28: 0000000000000001 +[10105.376874] x27: ffff000076fa80c8 x26: 0000000000000004 +[10105.382185] x25: 0000000000000030 x24: 0000000000000000 +[10105.387495] x23: 0000000000000000 x22: 0000000000000038 +[10105.392807] x21: 000000000000000c x20: ffff000076fa80c8 +[10105.398119] x19: ffff000076fa8000 x18: 0000000000000000 +[10105.403429] x17: 0000000000000000 x16: 0000000000000000 +[10105.408741] x15: 0000000000000000 x14: fefefefefefefeff +[10105.414052] x13: 0000000000000000 x12: 0000000000000fe0 +[10105.419364] x11: 0000000000000fe0 x10: ffff000076709020 +[10105.424675] x9 : 0000000000000000 x8 : 00000000000000a0 +[10105.429986] x7 : ffff000076fa80f4 x6 : 0000000000000030 +[10105.435297] x5 : 0000000000000000 x4 : 0000000000000000 +[10105.440609] x3 : 0000000000000000 x2 : ffff00006f276040 +[10105.445920] x1 : ffff000075633ab8 x0 : 0000000000000030 +[10105.451232] Call trace: +[10105.453676] atomic64_try_cmpxchg_acquire.constprop.22+0x8/0x34 +[10105.459600] ubifs_garbage_collect+0xb4/0x334 +[10105.463956] ubifs_budget_space+0x398/0x458 +[10105.468139] ubifs_create+0x50/0x180 +[10105.471712] path_openat+0x6a0/0x9b0 +[10105.475284] do_filp_open+0x34/0x7c +[10105.478771] do_sys_open+0x78/0xe4 +[10105.482170] __arm64_sys_openat+0x1c/0x24 +[10105.486180] el0_svc_handler+0x84/0xc8 +[10105.489928] el0_svc+0x8/0xc +[10105.492808] Code: 52800013 17fffffb d2800003 f9800011 (c85ffc05) +[10105.498903] ---[ end trace 46b721d93267a586 ]--- + +To reproduce the problem: + +1. Filesystem initially mounted read-only, free space fixup flag set. + +2. mount -o remount,rw + +3. it takes some time (free space fixup running) + ... try to terminate running mount by CTRL-C + ... does not respond, only after free space fixup is complete + ... then "ubifs_remount_fs: cannot spawn "ubifs_bgt0_0", error -4" + +4. mount -o remount,rw + ... now finished instantly (fixup already done). + +5. Create file or just unmount the filesystem and we get the oops. + +Cc: +Fixes: b50b9f408502 ("UBIFS: do not free write-buffers when in R/O mode") +Signed-off-by: Petr Cvachoucek +Signed-off-by: Richard Weinberger +Signed-off-by: Greg Kroah-Hartman +--- + fs/ubifs/super.c | 1 - + 1 file changed, 1 deletion(-) + +--- a/fs/ubifs/super.c ++++ b/fs/ubifs/super.c +@@ -1695,7 +1695,6 @@ out: + kthread_stop(c->bgt); + c->bgt = NULL; + } +- free_wbufs(c); + kfree(c->write_reserve_buf); + c->write_reserve_buf = NULL; + vfree(c->ileb_buf);