From 9eb78c25327548b905598975aa3ded4ef244b94a Mon Sep 17 00:00:00 2001 From: Artem Labazov <123321artyom@gmail.com> Date: Mon, 7 Dec 2020 09:04:36 +0900 Subject: [PATCH 1/2] exfat: Avoid allocating upcase table using kcalloc() The table for Unicode upcase conversion requires an order-5 allocation, which may fail on a highly-fragmented system: pool-udisksd: page allocation failure: order:5, mode:0x40dc0(GFP_KERNEL|__GFP_COMP|__GFP_ZERO), nodemask=(null), cpuset=/,mems_allowed=0 CPU: 4 PID: 3756880 Comm: pool-udisksd Tainted: G U 5.8.10-200.fc32.x86_64 #1 Hardware name: Dell Inc. XPS 13 9360/0PVG6D, BIOS 2.13.0 11/14/2019 Call Trace: dump_stack+0x6b/0x88 warn_alloc.cold+0x75/0xd9 ? _cond_resched+0x16/0x40 ? __alloc_pages_direct_compact+0x144/0x150 __alloc_pages_slowpath.constprop.0+0xcfa/0xd30 ? __schedule+0x28a/0x840 ? __wait_on_bit_lock+0x92/0xa0 __alloc_pages_nodemask+0x2df/0x320 kmalloc_order+0x1b/0x80 kmalloc_order_trace+0x1d/0xa0 exfat_create_upcase_table+0x115/0x390 [exfat] exfat_fill_super+0x3ef/0x7f0 [exfat] ? sget_fc+0x1d0/0x240 ? exfat_init_fs_context+0x120/0x120 [exfat] get_tree_bdev+0x15c/0x250 vfs_get_tree+0x25/0xb0 do_mount+0x7c3/0xaf0 ? copy_mount_options+0xab/0x180 __x64_sys_mount+0x8e/0xd0 do_syscall_64+0x4d/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xa9 Make the driver use kvcalloc() to eliminate the issue. Fixes: 370e812b3ec1 ("exfat: add nls operations") Cc: stable@vger.kernel.org #v5.7+ Signed-off-by: Artem Labazov <123321artyom@gmail.com> Signed-off-by: Namjae Jeon --- fs/exfat/nls.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/fs/exfat/nls.c b/fs/exfat/nls.c index 675d0e7058c5..314d5407a1be 100644 --- a/fs/exfat/nls.c +++ b/fs/exfat/nls.c @@ -659,7 +659,7 @@ static int exfat_load_upcase_table(struct super_block *sb, unsigned char skip = false; unsigned short *upcase_table; - upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL); + upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL); if (!upcase_table) return -ENOMEM; @@ -715,7 +715,7 @@ static int exfat_load_default_upcase_table(struct super_block *sb) unsigned short uni = 0, *upcase_table; unsigned int index = 0; - upcase_table = kcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL); + upcase_table = kvcalloc(UTBL_COUNT, sizeof(unsigned short), GFP_KERNEL); if (!upcase_table) return -ENOMEM; @@ -803,5 +803,5 @@ load_default: void exfat_free_upcase_table(struct exfat_sb_info *sbi) { - kfree(sbi->vol_utbl); + kvfree(sbi->vol_utbl); } From e14fd4ba8fb47fcf5f244366ec01ae94490cd86a Mon Sep 17 00:00:00 2001 From: Andi Kleen Date: Tue, 22 Dec 2020 09:40:10 -0800 Subject: [PATCH 2/2] x86/split-lock: Avoid returning with interrupts enabled When a split lock is detected always make sure to disable interrupts before returning from the trap handler. The kernel exit code assumes that all exits run with interrupts disabled, otherwise the SWAPGS sequence can race against interrupts and cause recursing page faults and later panics. The problem will only happen on CPUs with split lock disable functionality, so Icelake Server, Tiger Lake, Snow Ridge, Jacobsville. Fixes: ca4c6a9858c2 ("x86/traps: Make interrupt enable/disable symmetric in C code") Fixes: bce9b042ec73 ("x86/traps: Disable interrupts in exc_aligment_check()") # v5.8+ Signed-off-by: Andi Kleen Cc: Peter Zijlstra Cc: Fenghua Yu Cc: Tony Luck Reviewed-by: Thomas Gleixner Signed-off-by: Linus Torvalds --- arch/x86/kernel/traps.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/traps.c b/arch/x86/kernel/traps.c index fb55981f2a0d..7f5aec758f0e 100644 --- a/arch/x86/kernel/traps.c +++ b/arch/x86/kernel/traps.c @@ -303,11 +303,12 @@ DEFINE_IDTENTRY_ERRORCODE(exc_alignment_check) local_irq_enable(); if (handle_user_split_lock(regs, error_code)) - return; + goto out; do_trap(X86_TRAP_AC, SIGBUS, "alignment check", regs, error_code, BUS_ADRALN, NULL); +out: local_irq_disable(); }